Melasma

Overview

Definition

Melasma, also known as chloasma, is a benign Benign Fibroadenoma condition of 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 characterized by hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi in sun-exposed areas.

Epidemiology

• Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency varies greatly: 1.5%–15.5%
• Sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria: 9 times more common in women than men
• Age:
  • Rare before puberty Puberty Puberty is a complex series of physical, psychosocial, and cognitive transitions usually experienced by adolescents (11-19 years of age). Puberty is marked by a growth in stature and the development of secondary sexual characteristics, achievement of fertility, and changes in most body systems. Puberty
  • More common in reproductive years
• Race:
  • Higher prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency in individuals with darker 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 tones
  • More common in Hispanics and Asians

Etiology

• Sunlight/ultraviolet (UV) radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma exposure
• Hormonal factors: 
  • Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care (melasma is often called the “mask of pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care”)
  • Use of oral contraceptive Oral contraceptive Compounds, usually hormonal, taken orally in order to block ovulation and prevent the occurrence of pregnancy. The hormones are generally estrogen or progesterone or both. Benign Liver Tumors pills (OCPs)
  • Hormone replacement therapy Hormone Replacement Therapy Hormone replacement therapy (HRT) is used to treat symptoms associated with female menopause and in combination to suppress ovulation. Risks and side effects include uterine bleeding, predisposition to cancer, breast tenderness, hyperpigmentation, migraine headaches, hypertension, bloating, and mood changes. Noncontraceptive Estrogen and Progestins ( HRT HRT Hormone replacement therapy (HRT) is used to treat symptoms associated with female menopause and in combination to suppress ovulation. Risks and side effects include uterine bleeding, predisposition to cancer, breast tenderness, hyperpigmentation, migraine headaches, hypertension, bloating, and mood changes. Noncontraceptive Estrogen and Progestins)
• Photosensitizing medications
• Genetic predisposition
• Strong association with thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy disorders

Pathophysiology

Hyperactive melanocytes Melanocytes Mammalian pigment cells that produce melanins, pigments found mainly in the epidermis, but also in the eyes and the hair, by a process called melanogenesis. Coloration can be altered by the number of melanocytes or the amount of pigment produced and stored in the organelles called melanosomes. The large non-mammalian melanin-containing cells are called melanophores. Skin: Structure and Functions deposit excess melanin Melanin Insoluble polymers of tyrosine derivatives found in and causing darkness in skin (skin pigmentation), hair, and feathers providing protection against sunburn induced by sunlight. Carotenes contribute yellow and red coloration. Seborrheic Keratosis in the epidermis Epidermis The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of epithelium: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis). Skin: Structure and Functions and dermis Dermis A layer of vascularized connective tissue underneath the epidermis. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are sweat glands; hair follicles; and sebaceous glands. Skin: Structure and Functions of 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.

Clinical Presentation and Diagnosis

Clinical presentation

Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship develop hyperpigmented lesions.

• Occurs on any sun-exposed area of the body, most commonly: 
  • Cheeks
  • Chin
  • Forehead
  • Upper lip
• Appearance:
  • Tan or brown
  • Well demarcated
  • Splotchy (irregular)
  • Symmetric
  • Macules or patches Patches Vitiligo 

Diagnosis

The diagnosis of melasma is clinical.

Management and Prognosis

Management

• General management:
  • Minimize sun exposure.
  • Sunscreen Sunscreen Chemical or physical agents that protect the skin from sunburn and erythema by absorbing or blocking ultraviolet radiation. Melanoma
  • Consider discontinuation of or alternatives to HRT HRT Hormone replacement therapy (HRT) is used to treat symptoms associated with female menopause and in combination to suppress ovulation. Risks and side effects include uterine bleeding, predisposition to cancer, breast tenderness, hyperpigmentation, migraine headaches, hypertension, bloating, and mood changes. Noncontraceptive Estrogen and Progestins and OCPs.
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship should be screened for thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy disease.
• Topical depigmenting agents are the 1st-line treatment:
  • Hydroquinone cream
  • Azelaic acid Azelaic Acid Acne Vulgaris
  • Topical retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies (tretinoin)
• Chemical peels or laser therapy Laser Therapy The use of photothermal effects of lasers to coagulate, incise, vaporize, resect, dissect, or resurface tissue. Glaucoma are 2nd-line options if topical management fails.

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

• Melasma associated with pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care often spontaneously fades within a year of delivery.
• Recurrence is common with sun exposure, no matter what the initial inciting event.

Differential Diagnosis

• Hori’s nevus Nevus Nevi (singular nevus), also known as “moles,” are benign neoplasms of the skin. Nevus is a non-specific medical term because it encompasses both congenital and acquired lesions, hyper- and hypopigmented lesions, and raised or flat lesions. Nevus/Nevi: hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi condition commonly seen in Asian populations, particularly in Chinese and Japanese women of reproductive age. Hori’s nevus Nevus Nevi (singular nevus), also known as “moles,” are benign neoplasms of the skin. Nevus is a non-specific medical term because it encompasses both congenital and acquired lesions, hyper- and hypopigmented lesions, and raised or flat lesions. Nevus/Nevi is an acquired condition that often presents as bilateral, speckled, blue-gray to gray-brown macules on the cheeks, but may also affect other parts of the face. The diagnosis is clinical. Management is typically with laser therapy Laser Therapy The use of photothermal effects of lasers to coagulate, incise, vaporize, resect, dissect, or resurface tissue. Glaucoma and chemical peels.
• Riehl melanosis Melanosis Disorders of increased melanin pigmentation that develop without preceding inflammatory disease. Primary Biliary Cholangitis: also known as pigmented contact dermatitis Contact dermatitis A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms. Male Genitourinary Examination, a 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 condition caused by cosmetic ingredients. Presents with onset of erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion and pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema), followed by a diffuse, reticulated hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi of 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. The face and neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess are often involved. The diagnosis is clinical, but patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes testing can be done to identify the offending agent. Management includes avoiding the offending agent, skin-protective measures, and skin-lightening treatments.
• Discoid lupus erythematosus Discoid Lupus Erythematosus Alopecia: most common form of cutaneous lupus. The condition presents with circular, red or purplish scaly plaques, and most commonly occurs on the head and neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess. Hyperpigmented lesions can be interspersed with areas of scarring Scarring Inflammation and hypopigmentation Hypopigmentation A condition caused by a deficiency or a loss of melanin pigmentation in the epidermis, also known as hypomelanosis. Hypopigmentation can be localized or generalized, and may result from genetic defects, trauma, inflammation, or infections. Malassezia Fungi. Lesions are also photosensitive. The diagnosis is made with identification Identification Defense Mechanisms of autoantibodies Autoantibodies Antibodies that react with self-antigens (autoantigens) of the organism that produced them. Blotting Techniques. Steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors and anti-malarial medications are used for management.
• Solar lentigo: hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi condition caused by chronic and excessive sun exposure. Presents as tan or dark-brown macules in sun-exposed areas of 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. The diagnosis is clinical, but biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma may be performed to rule out 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 cancer. Management is with cryotherapy Cryotherapy A form of therapy consisting in the local or general use of cold. The selective destruction of tissue by extreme cold or freezing is cryosurgery. Chondrosarcoma or lasers.
• Phototoxic dermatitis Dermatitis Any inflammation of the skin. Atopic Dermatitis (Eczema): a 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 reaction secondary to the use of a systemic or topical phototoxic medication that causes increased sensitivity of 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 to UV radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present similar to a severe sunburn with erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion in sun-exposed regions. Vesicles Vesicles Female Genitourinary Examination and blisters may also develop. The diagnosis is usually clinical. Management can include avoidance of sun exposure and phototoxic agents, topical or systemic corticosteroids Corticosteroids Chorioretinitis, and cold compresses.