Vesicoureteral Reflux
Overview Definition Vesicoureteral reflux (VUR) is the retrograde flow of urine from the bladder into the upper urinary tract. Epidemiology The most common urinary finding in children: Occurs in 1%–2% of children < 2 years of age Prevalence is 15% in children with prenatal hydronephrosis 3 times more common in white children than Black children […]
Encephalitis
Overview Definition Encephalitis is an inflammation of the brain parenchyma caused by an infection that is usually viral and presents as diffuse or focal neuropsychologic dysfunction. Epidemiology Classification There are 2 main types of encephalitis: Etiology Viral encephalitis is the most common form of encephalitis. Bacterial, fungal, and parasitic encephalitides are extremely rare. Viral causes: […]
Methemoglobinemia
Overview Definition Methemoglobinemia occurs when RBCs contain elevated methemoglobin levels (normal range in adults is 0%–3%). Leads to functional anemia Cyanosis occurs at levels > 10%–15%. Fatal at levels > 70% Methemoglobin is a form of hemoglobin in which ferrous (Fe2+) heme iron is oxidized to the ferric (Fe3+) state, which is unable to bind […]
Imaging of the Lungs and Pleura
Introduction Before interpreting any image, the physician should take certain preparatory steps. The same systematic approach should be followed every time. Chest X-ray Indication Medical indications: Nonmedical indications: Advantages: Disadvantages: Exam technique Positioning: Positioning for specific views: Penetration: Penetration is the degree to which radiation has passed through body, resulting in a darker or lighter […]
Autosomal dominant polycystic kidney disease (ADPKD)
Epidemiology and Etiology Epidemiology Polycystic kidney disease (PKD) affects about 500,000 people in the United States. One of the 2 main types of PKD is autosomal dominant polycystic kidney disease (ADPKD). Etiology Clinical Presentation The age of symptom onset is variable, but typically in adulthood. Patients with PKD1 mutation present with symptoms earlier than patients […]
Autosomal Recessive Polycystic Kidney Disease (ARPKD)
Epidemiology and Etiology Epidemiology Polycystic kidney disease (PKD) affects about 500,000 people in the United States. Autosomal recessive polycystic kidney disease (ARPKD) (formerly known as infantile PKD), is 1 of the 2 main types of PKD. Etiology Clinical Presentation General manifestations Manifestations vary by age and affect the following: Antenatal and neonatal Infancy and childhood […]
Bowenoid Papulosis
Overview Definition Low-grade squamous cell carcinoma (SCC) in situ of the genitalia (although extragenital lesions have been reported) Induced by human HPV infection: Oncogenic genotypes (e.g., HPV 16, 18, and 31) Sexually transmitted condition Overall course of disease: Generally regresses spontaneously In rare cases, may transform into invasive SCC (< 1 %) Epidemiology The condition […]
Bowen Disease and Erythroplasia of Queyrat
Bowen Disease Squamous cell carcinoma (SCC) in situ affecting any area of the body: Represents a thin skin cancer that is localized to the epidermis 3%–5% of cases progress to invasive SCC. Annual incidence among white individuals is 14.9 cases per 100,000. Risk factors: Sun exposure Immunosuppression Fair complexion Smoking Arsenic exposure HPV infection (type […]
Leukoplakia
Overview Definition Epidemiology Risk factors Risk factors are similar to those for squamous cell carcinoma. Pathophysiology Clinical Presentation General findings Homogeneous leukoplakia This form is less likely to be malignant and is characterized by: Nonhomogeneous leukoplakia Nonhomogenous leukoplakia presents a higher risk of malignant transformation and may appear: Locations Diagnosis and Management Diagnosis Biopsy is […]
Secondary Skin Lesions
Scales Scales are dry or greasy masses of keratin that represent thickened stratum corneum. Characteristic types of scales are: Crust Erosion Excoriation Excoriation is a linear abrasion produced by mechanical means (scratching, rubbing, or picking) that usually involves only the epidermis but can reach the papillary dermis. Ulcer Fissure Atrophy Lichenification Approach to Diagnosing Skin […]