Alopecia areata

Alopecia areata, also known as spot baldness, is a condition in which hair is lost from some or all areas of the body. Often it results in a few bald spots on the scalp, each about the size of a coin. Psychological stress may result. People are generally otherwise healthy. In a few cases, all the hair on the scalp or all body hair is lost and loss can be permanent. Alopecia areata, also known as spot baldness, is a condition in which hair is lost from some or all areas of the body. Often it results in a few bald spots on the scalp, each about the size of a coin. Psychological stress may result. People are generally otherwise healthy. In a few cases, all the hair on the scalp or all body hair is lost and loss can be permanent. Alopecia areata is believed to be an autoimmune disease resulting from a breach in the immune privilege of the hair follicles. Risk factors include a family history of the condition. Among identical twins if one is affected the other has about a 50% chance of also being affected. The underlying mechanism involves failure by the body to recognize its own cells with subsequent immune mediated destruction of the hair follicle. There is no cure for the condition. Efforts may be used to try to speed hair regrowth such as cortisone injections. Sunscreen, head coverings to protect from cold and sun, and glasses if the eyelashes are missing is recommended. In some cases the hair regrows and the condition does not reoccur. In others hair loss and regrowth occurs over years. Among those in whom all body hair is lost less than 10% recover. About 0.15% of people are affected at any one time and 2% of people are affected at some point in time. Onset is usually in childhood. Males and females have the condition in equal numbers. The condition does not affect a person's life expectancy. Typical first symptoms of alopecia areata are small bald patches. The underlying skin is unscarred and looks superficially normal. Although these patches can take many shapes, they are usually round or oval. Alopecia areata most often affects the scalp and beard, but may occur on any part of the body with hair. Different areas of the skin may exhibit hair loss and regrowth at the same time. The disease may also go into remission for a time, or may be permanent. It is common in children. The area of hair loss may tingle or be painful. The hair tends to fall out over a short period of time, with the loss commonly occurring more on one side of the scalp than the other. Exclamation point hairs, narrower along the length of the strand closer to the base, producing a characteristic 'exclamation point' appearance, are often present. These hairs are very short (3–4 mm) and can be seen surrounding the bald patches. When healthy hair is pulled out, at most a few should come out, and ripped hair should not be distributed evenly across the tugged portion of the scalp. In cases of alopecia areata, hair will tend to pull out more easily along the edge of the patch where the follicles are already being attacked by the body's immune system than away from the patch where they are still healthy. Nails may have pitting or trachyonychia.