Skin diseases

Birthmarks	Congenital (present at birth) disorders of the dermal capillaries
Ringworm	Fungal infection that produces patchy scaling and inflammatory response in the skin
Eczema and dermatitis	Inflammatory conditions of the skin caused by allergy, infection, poor circulation, or exposure to chemical or environmental factors
Frostbite	white skin caused by extreme cold temperatures, the skin of his right ear became infected
Psoriasis	Chronic skin disease characterized by thicker-than-normal epidermal layer (stratum corneum) that sloughs to produce large, silvery scales; bleeding may occur if the scales are scraped away
Vitiligo	Development of patches of white skin where melanocytes are destroyed, apparently by an autoimmune response
Alopecia areata	often called spot baldness, involves varying degrees of hair loss and can affect all areas of the body. The condition is most likely due to an autoimmune response, where the defense cells of the body destroy normal, healthy cells. Regrowth of hair occurs in many individuals, but some experience permanent hair loss.
Skin Cancer	result from damage caused by the ultraviolet (UV) radiation in sunlight.
Basal cell carcinoma	the most common type, affects cells in the stratum basale. Basal cell carcinomas have a varied appearance. Some are open sores that bleed, ooze, or crust for several weeks.
Squamous cell carcinoma	the second most common type of skin cancer. Squamous cell carcinoma affects cells in the stratum spinosum and can appear as a wartlike growth; a persistent, scaly red patch; an open sore; or an elevated growth with a central depression.
Melanoma	the least common, but most deadly, type of skin can- cer, accounting for over 77% of the skin can- cer deaths in the United States. Because they arise from melanocytes, most melanomas are black or brown, but occasionally a melanoma stops producing melanin and appears skin- colored, pink, red, or purple.
Bacterial Infections
Impetigo	Small blisters containing pus; easily rupture to form a thick, yellowish crust; usually aects children
Erysipelas	Swollen patches in the skin caused by the bacterium Streptococcus pyogenes
Decubitus ulcers (bedsores, pressure sores)	Develop in people who are bedridden or confined to a wheelchair; compression of tissue and reduced circulation result in destruction of the skin and subcutaneous tissue, which later become infected by bacteria, forming ulcers
Acne	the most common skin condition in the United States. Though 80% of all American adolescents develop acne, adults can also be affected by it.
Viral Infections
Rubeola (measles)	Skin lesions; caused by a virus contracted through the respiratory tract; may develop into pneumonia or infect the brain, causing damage
Rubella (German measles)	Skin lesions; usually mild viral disease contracted through the respiratory tract; may be dangerous if contracted during pregnancy because the virus can cross the placenta and damage the fetus
Chickenpox	Skin lesions; usually mild viral disease contracted through the respiratory tract
Shingles	Painful skin lesions; caused by the chickenpox virus after childhood infection; can recur when the dormant virus is activated by trauma, stress, or another illness
Cold sores (fever blisters)	Skin lesions; caused by herpes simplex I virus; transmitted by oral or respiratory routes; lesions recur
Genital herpes	Genital lesions; caused by herpes simplex II virus; transmitted by sexual contact