Dog and Cat Bites (Clinical)

Overview

Epidemiology^[1,3,4]

International data are lacking, but statistics in the United States include:

• 3–6 million animal bites per year
• Most cause only minor wounds, but 1 in 5 cases requires medical attention Attention Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating. Psychiatric Assessment
• 2.5% require hospitalization Hospitalization The confinement of a patient in a hospital. Delirium
• Increased frequency in rural areas

Microbiology^[3]

In addition to the risk of contracting the rabies Rabies Acute viral CNS infection affecting mammals, including humans. It is caused by rabies virus and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf. Rabies Virus virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology from an animal bite, wound infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease can be caused by the following organisms:

Risk factors for bite-wound infection^[6-9]

Patient-related factors:

• Late presentation 
• Immunosuppression:
  • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus
  • Chemotherapy Chemotherapy Osteosarcoma
  • HIV HIV Anti-HIV Drugs
  • Sickle cell disease Sickle cell disease Sickle cell disease (SCD) is a group of genetic disorders in which an abnormal Hb molecule (HbS) transforms RBCs into sickle-shaped cells, resulting in chronic anemia, vasoocclusive episodes, pain, and organ damage. Sickle Cell Disease
  • Asplenia Asplenia Asplenia is the absence of splenic tissue or function and can stem from several factors ranging from congenital to iatrogenic. There is a distinction between anatomic asplenia, which is due to the surgical removal of the spleen, and functional asplenia, which is due to a condition that leads to splenic atrophy, infarct, congestion, or infiltrative disease. Asplenia
• Venous stasis or vascular disease

Bite-related factors:

• Cat bite (results in deeper bacterial inoculation) 
• Significant tissue destruction ( crush injury Crush injury Excessive compression of parts of the body that causes muscle swelling, fracture, and/or neurological disturbances in the affected areas. Crush injury with systemic manifestations is referred to as crush syndrome. Crush Syndrome)
• Hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy or foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy involvement 
• Location near a joint or prosthetic device

Clinical Presentation

General characteristics^[2,3]

Important history to elicit^[3,4]

• Time of occurrence (how long since bite)
• Circumstances 
• Type of animal 
• Status of animal ( rabies Rabies Acute viral CNS infection affecting mammals, including humans. It is caused by rabies virus and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf. Rabies Virus risk)
• Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
• Patient risk factors for wound infection

Important physical exam findings^[3-5]

• Wound exploration:
  • Foreign bodies ( teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth: Anatomy, clothing)
  • Local tissue destruction 
  • Deep structure injuries
• Signs of cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis or deep tissue infection (more common in cat bites Cat bites Dog and cat bites can cause superficial and deep tissue destruction, as well as serious wound infections. Cat bites are more frequent in adult women and result in puncture wounds. Dog and Cat Bites):
  • Erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion
  • Swelling Swelling Inflammation
  • Purulent discharge Purulent Discharge Dacryocystitis
  • Warmth  
• Local and distal assessment: 
  • Vascular injury
  • Neurologic damage
  • Tendon rupture 
  • Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types injuries ( skull Skull The skull (cranium) is the skeletal structure of the head supporting the face and forming a protective cavity for the brain. The skull consists of 22 bones divided into the viscerocranium (facial skeleton) and the neurocranium. Skull: Anatomy and cervical spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy fractures in infants and young children)
  • Joint space violation

Diagnosis

The diagnosis of a cat or dog bite is clinical, but the following may be utilized in select cases:

• Wound cultures:
  • Can be done if wound is infected in order to guide antibiotic therapy
  • Samples from fresh wounds are not valuable.
• Blood cultures should be done in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock.

Management

Management may vary based on practice location. The following information is based on US and UK guidelines.

General considerations

• Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship should be urged to seek prompt care.
• In the United States, physicians Physicians Individuals licensed to practice medicine. Clinician–Patient Relationship are required by law to report animal bites. 
• Prophylaxis Prophylaxis Cephalosporins:
  • Tetanus Tetanus Tetanus is a bacterial infection caused by Clostridium tetani, a gram-positive obligate anaerobic bacterium commonly found in soil that enters the body through a contaminated wound. C. tetani produces a neurotoxin that blocks the release of inhibitory neurotransmitters and causes prolonged tonic muscle contractions. Tetanus immunization^[7,8,10,11]
    • For clean wounds, administer vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination:
      • If < 3 previous doses
      • If last dose > 10 years ago
    • Contaminated wounds:
      • Give vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination if last dose ≥ 5 years ago, < 3 doses of primary vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination series, or unknown vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination status.
      • Human tetanus Tetanus Tetanus is a bacterial infection caused by Clostridium tetani, a gram-positive obligate anaerobic bacterium commonly found in soil that enters the body through a contaminated wound. C. tetani produces a neurotoxin that blocks the release of inhibitory neurotransmitters and causes prolonged tonic muscle contractions. Tetanus immune globulin (TIG) if patient has had < 3 doses of toxoid Toxoid Preparations of pathogenic organisms or their derivatives made nontoxic and intended for active immunologic prophylaxis. They include deactivated toxins. Anatoxin toxoids are distinct from anatoxins that are tropanes found in cyanobacteria. Vaccination vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination, has HIV HIV Anti-HIV Drugs, or is severely immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis
  • Rabies Rabies Acute viral CNS infection affecting mammals, including humans. It is caused by rabies virus and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf. Rabies Virus immunization (if animal status is unknown):^[7,8,12]
    • No previous vaccinations: 4 doses of rabies Rabies Acute viral CNS infection affecting mammals, including humans. It is caused by rabies virus and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf. Rabies Virus vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination over 2 weeks (given IM on days 0, 3, 7, and 14), plus rabies Rabies Acute viral CNS infection affecting mammals, including humans. It is caused by rabies virus and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf. Rabies Virus immunoglobulin (20 IU/kg body weight) on day 0
    • Rabies Rabies Acute viral CNS infection affecting mammals, including humans. It is caused by rabies virus and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf. Rabies Virus vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination in the past: typically only 2 doses of rabies Rabies Acute viral CNS infection affecting mammals, including humans. It is caused by rabies virus and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf. Rabies Virus vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination after an exposure (given on days 0 and 3)

Wound management^[6-10,13]

• Direct pressure to control bleeding 
• Wound irrigation
  • Cleanse the wound surface with clean water or saline. 
  • 1% povidone– iodine Iodine A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126. 90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically. Thyroid Hormones or 1% benzalkonium chloride Chloride Inorganic compounds derived from hydrochloric acid that contain the Cl- ion. Electrolytes may be used. 
  • Irrigate open wounds with a large volume of sterile Sterile Basic Procedures water or saline solution.
  • Moderate-pressure irrigation: 18-gauge angiocatheter with a large-volume syringe is effective. 
• Explore deep tissues for tendon and bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types damage. ( X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests may be needed.)
• Search for and remove foreign bodies.
• Debride devitalized tissue.
• Wound closure:
  • Primary intention Primary intention When the tissue surface edges have been approximated Wound Healing is indicated for:
    • Minimal damage
    • Easily cleaned
    • Low risk of infection
  • Secondary intention Secondary intention When there are significant tissue losses and the wound surface cannot be brought together (e.g., lacerations, burns, and ulcers) Wound Healing is suitable for:
    • Delayed presentation
    • Wounds on hands and feet
    • Contaminated wounds
    • Evidence of inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation
    • Deep structure involvement

Management of infected wounds

• Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease are usually polymicrobial (with pathogens that include aerobic and anaerobic organisms):
  •  Those on the human skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions (staphylococci and streptococci)
  • Oral animal flora (commonly include Pasteurella spp. and anaerobes Anaerobes Lincosamides)
• For wounds that are proven to be infected, antibiotic agent(s) should be given for 5–14 days.

Outpatient management:

• Antibiotic therapy (adult):^[6-8,10]
  • 1st-line therapy: amoxicillin Amoxicillin A broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration. Penicillins–clavulanate
  • Alternative (e.g., for penicillin Penicillin Rheumatic Fever allergy Allergy An abnormal adaptive immune response that may or may not involve antigen-specific IgE Type I Hypersensitivity Reaction): 1 of the following agents plus anaerobic coverage ( metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess or clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides):
    • Doxycycline
    • Trimethoprim Trimethoprim The sulfonamides are a class of antimicrobial drugs inhibiting folic acid synthesize in pathogens. The prototypical drug in the class is sulfamethoxazole. Although not technically sulfonamides, trimethoprim, dapsone, and pyrimethamine are also important antimicrobial agents inhibiting folic acid synthesis. The agents are often combined with sulfonamides, resulting in a synergistic effect. Sulfonamides and Trimethoprim– sulfamethoxazole Sulfamethoxazole A bacteriostatic antibacterial agent that interferes with folic acid synthesis in susceptible bacteria. Its broad spectrum of activity has been limited by the development of resistance. Sulfonamides and Trimethoprim (TMP-SMX) 
    • Cefuroxime
    • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones or levofloxacin Levofloxacin The l-isomer of ofloxacin. Fluoroquinolones 
  • Alternative monotherapy: moxifloxacin Moxifloxacin A fluoroquinolone that acts as an inhibitor of DNA topoisomerase II and is used as a broad-spectrum antibacterial agent. Fluoroquinolones
  • Avoid the following (associated with ↓ activity against Pasteurella and fusobacteria Fusobacteria A genus of gram-negative, anaerobic, rod-shaped bacteria found in cavities of humans and other animals. No endospores are formed. Some species are pathogenic and occur in various purulent or gangrenous infections. Perianal and Perirectal Abscess):
    • Macrolides Macrolides Macrolides and ketolides are antibiotics that inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit and blocking transpeptidation. These antibiotics have a broad spectrum of antimicrobial activity but are best known for their coverage of atypical microorganisms. Macrolides and Ketolides
    • Dicloxacillin Dicloxacillin One of the penicillins which is resistant to penicillinase. Penicillins
    • Cephalexin
• Antibiotic therapy (pediatric):^[10]
  • 1st-line: amoxicillin Amoxicillin A broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration. Penicillins–clavulanate
  • Preferred alternative agents are cephalosporins Cephalosporins Cephalosporins are a group of bactericidal beta-lactam antibiotics (similar to penicillins) that exert their effects by preventing bacteria from producing their cell walls, ultimately leading to cell death. Cephalosporins are categorized by generation and all drug names begin with “cef-” or “ceph-.” Cephalosporins (extended-spectrum) or TMP-SMX, PLUS clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides.
    • Cefuroxime
    • TMP-SMX
    • Clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides
  • Fluoroquinolone use in children should be limited (if preferred alternatives are not safe or effective).

For severe infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease:

• Hospitalize patient for:
  • Worsening cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis
  • Suspected sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock
• Empiric ( broad-spectrum Broad-Spectrum Fluoroquinolones) IV antibiotic therapy for severe infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease:^[6-8,10]
  • Adults:
    • 1st-line: ampicillin Ampicillin Semi-synthetic derivative of penicillin that functions as an orally active broad-spectrum antibiotic. Penicillins– sulbactam Sulbactam A beta-lactamase inhibitor with very weak antibacterial action. The compound prevents antibiotic destruction of beta-lactam antibiotics by inhibiting beta-lactamases, thus extending their spectrum activity. Combinations of sulbactam with beta-lactam antibiotics have been used successfully for the therapy of infections caused by organisms resistant to the antibiotic alone. Cephalosporins or piperacillin Piperacillin Semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics. Penicillins– tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins
    • Alternative: 1 of the following agents plus anaerobic coverage ( metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess or clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides):
      • Ceftriaxone Ceftriaxone A broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears. Cephalosporins
      • Cefoxitin
      • Cefuroxime
      • Doxycycline
      • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones
      • Levofloxacin Levofloxacin The l-isomer of ofloxacin. Fluoroquinolones
      • Trimethoprim Trimethoprim The sulfonamides are a class of antimicrobial drugs inhibiting folic acid synthesize in pathogens. The prototypical drug in the class is sulfamethoxazole. Although not technically sulfonamides, trimethoprim, dapsone, and pyrimethamine are also important antimicrobial agents inhibiting folic acid synthesis. The agents are often combined with sulfonamides, resulting in a synergistic effect. Sulfonamides and Trimethoprim– sulfamethoxazole Sulfamethoxazole A bacteriostatic antibacterial agent that interferes with folic acid synthesis in susceptible bacteria. Its broad spectrum of activity has been limited by the development of resistance. Sulfonamides and Trimethoprim
    • Alternative monotherapy: moxifloxacin Moxifloxacin A fluoroquinolone that acts as an inhibitor of DNA topoisomerase II and is used as a broad-spectrum antibacterial agent. Fluoroquinolones or carbapenems Carbapenems A group of beta-lactam antibiotics in which the sulfur atom in the thiazolidine ring of the penicillin molecule is replaced by a carbon atom. Thienamycins are a subgroup of carbapenems which have a sulfur atom as the first constituent of the side chain. Carbapenems and Aztreonam (misses MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus coverage)
  • Pediatric:^[10]
    • Ampicillin Ampicillin Semi-synthetic derivative of penicillin that functions as an orally active broad-spectrum antibiotic. Penicillins– sulbactam Sulbactam A beta-lactamase inhibitor with very weak antibacterial action. The compound prevents antibiotic destruction of beta-lactam antibiotics by inhibiting beta-lactamases, thus extending their spectrum activity. Combinations of sulbactam with beta-lactam antibiotics have been used successfully for the therapy of infections caused by organisms resistant to the antibiotic alone. Cephalosporins
    • Alternative: 1 of the following agents plus anaerobic coverage ( clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides)
      • Cefuroxime
      • TMP-SMX
    • Alternative monotherapy: carbapenems Carbapenems A group of beta-lactam antibiotics in which the sulfur atom in the thiazolidine ring of the penicillin molecule is replaced by a carbon atom. Thienamycins are a subgroup of carbapenems which have a sulfur atom as the first constituent of the side chain. Carbapenems and Aztreonam
• Consult specialist:^[10,13]
  • Operative consult warranted for extensive wounds, partial flap avulsion, or complete tissue loss
  • Infectious disease consult to aid in definitive antibiotic regimen

Prophylaxis Prophylaxis Cephalosporins^[6-9]

Wounds at low risk for infection (e.g., abrasions Abrasions Corneal Abrasions, Erosion, and Ulcers) do not require antibiotic prophylaxis Prophylaxis Cephalosporins. Antibiotic prophylaxis Prophylaxis Cephalosporins (for 3–5 days) is indicated for:

High-risk wounds:

• Deep puncture wounds
• Crush injuries
• Wounds requiring surgical repair or after primary closure Primary Closure Gastroschisis
• Wounds near a bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types or joint
• Bites to the hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy, face, or genital area

High-risk conditions:

• Late presentation
• Immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
• Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus
• Splenectomy Splenectomy Surgical procedure involving either partial or entire removal of the spleen. Rupture of the Spleen
• Advanced liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease
• Postmastectomy
• Prosthetic joints Prosthetic joints Prostheses used to partially or totally replace a human or animal joint. Soft Tissue Abscess

Human Bites

Managed similar to dog and cat bites Cat bites Dog and cat bites can cause superficial and deep tissue destruction, as well as serious wound infections. Cat bites are more frequent in adult women and result in puncture wounds. Dog and Cat Bites with the addition of testing and treatment for potential exposure to HIV HIV Anti-HIV Drugs, hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus, and hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus.

Classification^[6,7,10]

• Closed-fist injury (when the fist strikes the teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth: Anatomy on another individual): most common
• Occlusive bite (when someone bites with sufficient force to break skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions)

Microbiology^[6,7,10]

Infection after a human bite is often polymicrobial. Common organisms include:

• Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus
• Staphylococcus Staphylococcus Staphylococcus is a medically important genera of Gram-positive, aerobic cocci. These bacteria form clusters resembling grapes on culture plates. Staphylococci are ubiquitous for humans, and many strains compose the normal skin flora. Staphylococcus
• Eikenella Eikenella A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in the human mouth and intestine. Organisms of this genus can be opportunistic pathogens. Dog and Cat Bites corrodens
• Corynebacterium Corynebacterium Corynebacteria are gram-positive, club-shaped bacilli. Corynebacteria are commonly isolated on tellurite or Loeffler’s media and have characteristic metachromatic granules. The major pathogenic species is Corynebacterium diphtheriae, which causes a severe respiratory infection called diphtheria. Corynebacterium
• Bacteroides Bacteroides Bacteroides is a genus of opportunistic, anaerobic, gram-negative bacilli. Bacteroides fragilis is the most common species involved in human disease and is part of the normal flora of the large intestine. Bacteroides

General considerations and evaluation^[6,7,10]

• Individuals with these injuries often present with an established infection (e.g., wounds with purulent discharge Purulent Discharge Dacryocystitis and/or swelling Swelling Inflammation)
• In hand-bite injuries, damage to the tendon sheath, fascia Fascia Layers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin; the deep fascia invests muscles, nerves, and other organs. Cellulitis, and metacarpal head need to be assessed carefully:
  • Examine the hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy with fingers extended and in a clenched-fist position.
  • Check for foreign material, infection, and neurovascular status.
  • Deep infection manifests as:
    • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways out of proportion to findings
    • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways on passive movement
    • Crepitus Crepitus Osteoarthritis and joint effusion Joint Effusion Septic Arthritis
    • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever and other systemic signs
• Evaluation:
  • Inflammatory markers (e.g., CRP) for clinically evident infection
  • Wound culture
  • Blood cultures for suspected bacteremia Bacteremia The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion. Glycopeptides
  • Test for potential exposure to HIV HIV Anti-HIV Drugs, hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus, and hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus.
  • Radiologic imaging

Management^[6,7,10]

• Extensive wound irrigation
• Tetanus Tetanus Tetanus is a bacterial infection caused by Clostridium tetani, a gram-positive obligate anaerobic bacterium commonly found in soil that enters the body through a contaminated wound. C. tetani produces a neurotoxin that blocks the release of inhibitory neurotransmitters and causes prolonged tonic muscle contractions. Tetanus immunization
• Postexposure prophylaxis Prophylaxis Cephalosporins ( HIV HIV Anti-HIV Drugs and hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus) as indicated
• Amoxicillin Amoxicillin A broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration. Penicillins–clavulanate prophylaxis Prophylaxis Cephalosporins should be given if the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions has been pierced (see above antibiotic therapy for dog and cat bites Cat bites Dog and cat bites can cause superficial and deep tissue destruction, as well as serious wound infections. Cat bites are more frequent in adult women and result in puncture wounds. Dog and Cat Bites).
• Alternative antibiotic regimen is similar to dog and cat bites Cat bites Dog and cat bites can cause superficial and deep tissue destruction, as well as serious wound infections. Cat bites are more frequent in adult women and result in puncture wounds. Dog and Cat Bites.
• Surgical consultation:
  • Clenched-fist injuries
  • Complex face injuries
  • Deep wounds
  • Evidence of neurovascular compromise
  • Infection in an immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis individual
• Debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome when indicated

Complications^[6,7,10]

• Transmission of:
  • Hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus
  • Hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus
  • HIV HIV Anti-HIV Drugs
  • Herpes simplex Herpes Simplex A group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluid-filled vesicles with a raised erythematous base on the skin or mucous membrane. It occurs as a primary infection or recurs due to a reactivation of a latent infection. Congenital TORCH Infections virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
• Tendon laceration Laceration Torn, ragged, mangled wounds. Blunt Chest Trauma
• Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease (particularly closed-fist injury):
  • Tenosynovitis
  • Septic arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis
  • Osteomyelitis Osteomyelitis Osteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus. Osteomyelitis
• Cosmetic deformities

Differential Diagnosis

• Snake Snake Limbless reptiles of the suborder serpentes. Snakebites bite: Envenomation at the bite site can cause edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema, erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion, warmth, bullae Bullae Erythema Multiforme, and necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage. Systemic symptoms such as nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics, diaphoresis, paresthesias Paresthesias Subjective cutaneous sensations (e.g., cold, warmth, tingling, pressure, etc.) that are experienced spontaneously in the absence of stimulation. Posterior Cord Syndrome, and altered sensorium may be present, which are not common in dog or cat bites Cat bites Dog and cat bites can cause superficial and deep tissue destruction, as well as serious wound infections. Cat bites are more frequent in adult women and result in puncture wounds. Dog and Cat Bites. The diagnosis is clinical. Management includes supportive care, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways control, hydration, and antivenom.  Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are monitored closely for shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock, coagulopathy, respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure, and renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome.
• Insect sting: Bee, wasp, and ant stings can cause envenomation with localized swelling Swelling Inflammation. Some patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will develop a severe allergic reaction, including anaphylaxis Anaphylaxis An acute hypersensitivity reaction due to exposure to a previously encountered antigen. The reaction may include rapidly progressing urticaria, respiratory distress, vascular collapse, systemic shock, and death. Type I Hypersensitivity Reaction. This does not occur with dog or cat bites Cat bites Dog and cat bites can cause superficial and deep tissue destruction, as well as serious wound infections. Cat bites are more frequent in adult women and result in puncture wounds. Dog and Cat Bites. The diagnosis is clinical. Management includes removing the stinger (if present), antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways control, and emergency care for anaphylaxis Anaphylaxis An acute hypersensitivity reaction due to exposure to a previously encountered antigen. The reaction may include rapidly progressing urticaria, respiratory distress, vascular collapse, systemic shock, and death. Type I Hypersensitivity Reaction.
• Scorpion sting: Most scorpion stings Scorpion stings Insect and scorpion stings are a rare cause of mortality. Hymenoptera insects and Centruroides scorpions can potentially lead to serious symptoms due to envenomation. Pain, swelling, erythema, and warmth are common at the site of a sting. Insect and Scorpion Stings are harmless. However, the bark scorpion is venomous. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will have pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and swelling Swelling Inflammation at the site of the sting. Systemic manifestations can include muscle spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy, diaphoresis, abnormal neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess and head movements, tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children, hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, and respiratory distress. The diagnosis is clinical. Management includes supportive care, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways control, benzodiazepines Benzodiazepines Benzodiazepines work on the gamma-aminobutyric acid type A (GABAA) receptor to produce inhibitory effects on the CNS. Benzodiazepines do not mimic GABA, the main inhibitory neurotransmitter in humans, but instead potentiate GABA activity. Benzodiazepines for muscle spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy, and antivenom.
• Spider Spider Arthropods of the class arachnida, order araneae. Except for mites and ticks, spiders constitute the largest order of arachnids, with approximately 37, 000 species having been described. The majority of spiders are harmless, although some species can be regarded as moderately harmful since their bites can lead to quite severe local symptoms. Spider Bites bites: The brown recluse spider Spider Arthropods of the class arachnida, order araneae. Except for mites and ticks, spiders constitute the largest order of arachnids, with approximately 37, 000 species having been described. The majority of spiders are harmless, although some species can be regarded as moderately harmful since their bites can lead to quite severe local symptoms. Spider Bites contains a necrotizing venom Necrotizing Venom Spider Bites, which can lead to a painful, blistering, necrotic wound, fevers, myalgias Myalgias Painful sensation in the muscles. Tick-borne Encephalitis Virus, hemolysis, seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures, and renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome. A black widow spider Spider Arthropods of the class arachnida, order araneae. Except for mites and ticks, spiders constitute the largest order of arachnids, with approximately 37, 000 species having been described. The majority of spiders are harmless, although some species can be regarded as moderately harmful since their bites can lead to quite severe local symptoms. Spider Bites’s neurotoxic venom Neurotoxic Venom Spider Bites can cause muscle cramping and rigidity Rigidity Continuous involuntary sustained muscle contraction which is often a manifestation of basal ganglia diseases. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Megacolon, unstable vital signs, lacrimation, salivation, ptosis Ptosis Cranial Nerve Palsies, and respiratory distress. The diagnosis is clinical. Management includes wound care, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways management, antivenom for black widow bites, and delayed debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome of necrotic tissue for brown recluse bites.