A rare genetic condition where the body can't process proteins adequately. More specifically, there are insufficient levels of the enzyme needed to break down an amino acid called leucine. This results in a build up of isovaleric acid which can harm ...

Acne is a skin condition that occurs when your hair follicles become plugged with oil and dead skin cells. It often causes whiteheads, blackheads or pimples, and usually appears on the face, forehead, chest, upper back and shoulders. Acne is most ...

Acne (acne vulgaris, common acne) is a disease of the hair follicles of the face, chest, and back that affects almost all teenagers during puberty -- the only exception being members of a few primitive Neolithic tribes living in isolatio...

Classical lissencephaly, also known as lissencephaly type I, is a brain malformation that may occur as an isolated abnormality (isolated lissencephaly sequence [ILS]) or in association with certain underlying syndromes (e.g., Miller-Dieker syndrom...

The term albinism typically refers to oculocutaneous (ok-u-low-ku-TAY-nee-us) albinism (OCA) — a group of inherited disorders where there is little or no production of the pigment melanin. The type and amount of melanin your body produces de...

Bacterial vaginosis is an abnormal vaginal condition that is characterized by vaginal discharge and results from an overgrowth of atypical bacteria in the vagina. Bacterial vaginosis is not dangerous, but it can cause disturbing sym...

Bad breath, also known as halitosis, is a condition characterized by an unpleasant odor coming from the mouth. It can be caused by a variety of factors, including poor oral hygiene, certain foods and drinks, smoking, dry mouth, gum disease, and ce...

Bile duct cancer, also called cholangiocarcinoma, is when unusual cells grow out of control inside your bile ducts. Those are thin tubes about 4 to 5 inches long that move a fluid called bile from your liver to your gallbladder and small intestine...

Bile duct cancer, also called cholangiocarcinoma, is when unusual cells grow out of control inside your bile ducts. Those are thin tubes about 4 to 5 inches long that move a fluid called bile from your liver to your gallbladder and small intestine...

Boil  A boil is a painful, pus-filled bump under your skin — the result of a bacterial infection of one or more hair follicles. Carbuncle  A carbuncle is a cluster of boils — painful, pus-filled bumps ...

Canker sores, also known as aphthous ulcers, are small, painful sores that develop on the inside of the mouth, on the gums, or on the tongue. They are usually round or oval in shape and have a white or yellow center with a red border. Canker sores...

Chanarin Dorfman syndrome is a rare hereditary disorder of fat (lipid) metabolism. It is characterized by scaly skin (ichthyosis), degeneration of the muscles (myopathy), and abnormal white blood cells with small spaces (vacuoles) filled with fat ...

A corneal ulcer is an open sore on the cornea, the clear dome-shaped surface that covers the front of the eye. It is usually caused by an infection, such as bacterial, viral, or fungal, or by an injury to the eye. Symptoms of a corneal ulcer inclu...

Cradle cap causes crusty or oily scaly patches on a baby's scalp. The condition isn't painful or itchy. But it can cause thick white or yellow scales that aren't easy to remove. Cradle cap usually clears up on its own in a few months. Home...

Mixed cryoglobulinemia is a rare disorder characterized by the presence of cryoglobulins in the blood. Cryoglobulins are abnormal proteins that thicken and clump together at cold temperatures, usually below 98.6 degrees Fahrenheit (the average hum...

Degos disease is an extremely rare disorder in which small and medium sized arteries become blocked (occlusive arteriopathy), restricting the flow of blood to affected areas. Degos disease usually causes characteristic skin lesions that may last f...

Degos disease is an extremely rare disorder in which small and medium sized arteries become blocked (occlusive arteriopathy), restricting the flow of blood to affected areas. Degos disease usually causes characteristic skin lesions that may last f...

Dental fluorosis is a condition that affects the teeth due to overexposure to fluoride during the early years of life. It can cause white or brown spots, streaks, or pits on the teeth, and in severe cases, it can lead to enamel erosion and discolo...

Geographic tongue, also known as benign migratory glossitis, is a harmless condition characterized by irregular patches on the surface of the tongue that resemble a map. These patches can vary in size, shape, and color, and may come and go over ti...

Lichen sclerosus is a chronic skin disorder that most commonly affects post-menopausal women. However, it is sometimes identified among pre-menopausal women, and, even more rarely, among males. When found in males, the disease is known as balaniti...

Halitosis, commonly known as bad breath, is a condition characterized by an unpleasant odor coming from the mouth. It can be caused by a variety of factors, including poor oral hygiene, certain foods and drinks, smoking, dry mouth, and underlying ...

Hyperlipoproteinemia type III, also known as dysbetalipoproteinemia or broad beta disease, is a rare genetic disorder characterized by improper breakdown (metabolism) of certain fatty materials known as lipids, specifically cholesterol and triglyc...

Lamellar ichthyosis is a rare genetic skin disorder. In lamellar ichthyosis, the skin cells are produced at a normal rate, but they do not separate normally at the surface of the outermost layer of skin (stratum corneum) and are not shed as quickl...

Ichthyosis vulgaris (ik-thee-O-sis vul-GAY-ris) is an inherited skin disorder in which dead skin cells accumulate in thick, dry scales on your skin's surface. The scales of ichthyosis vulgaris, sometimes called fish scale disease or fish s...

Kabuki syndrome is a rare, multisystem disorder characterized by multiple abnormalities including distinctive facial features, growth delays, varying degrees of intellectual disability, skeletal abnormalities, and short stature. A wide variety of ...

Epidermolysis bullosa (EB) is a genetic skin disorder characterized clinically by blister formation from mechanical trauma. There are four main types with additional sub-types identified. There is a spectrum of severity, and within each type, one ...

Leukoplakia is a condition characterized by thick, white patches that form on the mucous membranes of the mouth and sometimes the throat. These patches are caused by an overgrowth of cells and are often a result of chronic irritation or inflammati...

Granuloma annulare is a chronic degenerative skin disorder. The most common form is localized granuloma annulare, which is characterized by the presence of small, firm red or yellow colored bumps (nodules or papules) that appear arranged in a ring...

Lichen planus facts Lichen planus is a chronic recurrent rash of unknown cause with no established cure. Lichen planus generally affects adults and can involve any portion of the body, but it has a predilection for the wri...

Lichen Planus is a rare, recurrent, itchy rash or area of inflammatory eruptions (lesions) of unknown origin characterized by shiny reddish-purple spots on the skin and gray-white ones in the mouth. The disorder may present as itchy spots on the w...

Lichen Planus is a rare, recurrent, itchy rash or area of inflammatory eruptions (lesions) of unknown origin characterized by shiny reddish-purple spots on the skin and gray-white ones in the mouth. The disorder may present as itchy spots on the w...

Lichen sclerosus facts Lichen sclerosus is a long-term problem of the skin that mostly affects the genital and perianal areas. Lichen sclerosus is most commonly seen in post-menopausal women. It is uncommon in men and chil...

Onchocerciasis, also known as African River Blindness, is a parasitic infection caused by the filarial worm Onchocerca volvulus. It is transmitted to humans through the bite of an infected blackfly. Symptoms of the infection include severe itching...

Oral leukoplakia is a condition characterized by thick, white patches or plaques that form on the inside of the mouth, typically on the cheeks, gums, or tongue. These patches cannot be scraped off and may be rough or slightly raised. ...

Oral lichen planus is a chronic inflammatory condition that affects the mucous membranes inside the mouth. It is characterized by the presence of white, lacy patches or sores on the inside of the cheeks, gums, tongue, and other areas of the mouth....

Oral thrush, also known as oral candidiasis, is a fungal infection caused by the overgrowth of Candida albicans in the mouth. It typically appears as white, creamy patches on the tongue, inner cheeks, roof of the mouth, gums, or tonsils. Oral thru...

Retinoblastoma is a rare form of eye cancer that affects the retina, the light-sensitive tissue at the back of the eye. It is most commonly found in children under the age of five, and is caused by a genetic mutation. Symptoms of retinoblastoma in...

Russell-Silver syndrome (RSS) is a rare disorder characterized by intrauterine growth retardation and postnatal growth deficiency along with a handful of common physical characteristics and a range of other symptoms. The wide spectrum of phenotype...

Though they're not cancerous, sebaceous cysts can be irritating. A sebaceous cyst is a small lump or bump under the skin. This type of cyst is not cancerous. They are most often found on the face, neck, upper back, and upper chest,...

Reflex sympathetic dystrophy syndrome (RSDS), also known as complex regional pain syndrome, is a rare disorder of the sympathetic nervous system that is characterized by chronic, severe pain. The sympathetic nervous system is that part of the auto...

What are yeast infections? What are commonly known as "yeast" infections are caused by various species of a yeast-like fungus called Candida, particularly the species Candida albicans. Yeast organisms are part of the germs (including bacte...

Tonsillitis is an inflammation of the tonsils, which are two small glands located at the back of the throat. It is usually caused by a viral or bacterial infection and can result in symptoms such as sore throat, difficulty swallowing, fever, and s...

Tooth discoloration is when the color of the teeth changes from their natural shade to a different color, typically yellow, brown, or gray. This can be caused by a variety of factors, including: 1. Poor oral hygiene: Not brushing and ...

Esophageal atresia (EA) is a rare birth defect in which the esophagus (the tube that connects the throat with the stomach) does not develop normally. In infants with EA, the esophagus is usually separated into two parts, an upper and lower segment...

Trichomoniasis is a common sexually transmitted infection caused by a parasite. In women, trichomoniasis can cause a foul-smelling vaginal discharge, genital itching and painful urination. Men who have trichomoniasis typically have no symp...

Trichomoniasis is a common sexually transmitted infection caused by a parasite. In women, trichomoniasis can cause a foul-smelling vaginal discharge, genital itching and painful urination. Men who have trichomoniasis typically have no symp...

Tyrosinemia type I is a rare autosomal recessive genetic metabolic disorder characterized by lack of the enzyme fumarylacetoacetate hydrolase (FAH), which is needed for the final break down of the amino acid tyrosine. Failure to properly break dow...

Physical urticaria is a condition in which red (erythematous) allergic skin lesions and itching (pruritus) are produced by exposure to heat, cold, or contact with chemicals or plants. These are called wheals by the medical community and may range ...

Uveitis is an inflammation of the uvea, the middle layer of the eye that contains the blood vessels, iris, and ciliary body. It can cause pain, redness, and blurred vision. Uveitis can be caused by infection, injury, or autoimmune diseases. Treatm...

Vitiligo is a disease in which the pigment cells of the skin, melanocytes, are destroyed in certain areas. Vitiligo results in depigmented, or white, patches of skin in any location on the body. Vitiligo can be focal and l...

Alopecia areata is a disorder characterized by loss of hair. Sometimes, this means simply a few bare patches on the scalp. In other cases, hair loss is more extensive. Although the exact cause is not known, this is thought to be an autoimmune diso...

In ichthyosis vulgaris, the skin cells are produced at a normal rate, but they do not shed normally at the surface of the outermost layer of skin (stratum corneum) and are not shed as quickly as they should be. The result is a build-up of scale. F...

Weil syndrome, a rare infectious disorder, is a severe form of the bacterial infection caused by Leptospira bacteria known as leptospirosis. Weil syndrome is characterized by dysfunction of the kidneys and liver, abnormal enlargement of the liver ...

Yeast infection, also known as candidiasis, is a fungal infection caused by an overgrowth of the Candida fungus. It can occur in various parts of the body, including the mouth, throat, skin, and genital area. Symptoms of yeast infection may includ...