DefinitionAlopecia areata is a condition that causes round patches of hair loss. It can lead to total hair loss.
Alternative NamesAlopecia totalis; Alopecia universalis
Causes, incidence, and risk factorsThe cause of alopecia areata is unknown. About 1 in 5 people with this condition have a family history of alopecia.Alopecia areata is thought to be an autoimmune condition. This occurs when the immune system mistakenly attacks and destroys healthy body tissue.Alopecia areata is seen in men, women, and children. In a few people, hair loss may occur after a major life event such as an illness, pregnancy, or trauma. Forms of alopecia include:Alopecia areata -- patches of hair lossAlopecia totalis -- complete loss of scalp hairAlopecia universalis -- total loss of all body hair
SymptomsHair loss is usually the only symptom. A few people may also feel a burning sensation or itching.Alopecia areata usually begins as one to two patches of hair loss. Hair loss, is most often seen on the scalp. It may also occur in the beard, eyebrows, and arms or legs in some people.Patches where hair has fallen out are smooth and round in shape. They may be peach-colored. Hairs that look like exclamation points are sometimes seen at the edges of a bald patch.Loss of all scalp hair (alopecia totalis), often within 6 months after symptoms first start.Loss of all scalp and body hair (alopecia universalis).
Signs and testsA scalp biopsy may be done. Several blood tests may also be done to check for autoimmune conditions and thyroid problems.
TreatmentIf hair loss is not widespread, the hair will often regrow in a few months without treatment.Even for more severe hair loss, it is not clear how much treatment can help change the course of the condition.Common treatments may include:Steroid injection under the skin surfaceMedicines applied to the skin including corticosteroids, immunotherapy, and minoxidilUltraviolet light therapyWigs may be used to hide areas of hair loss.
Expectations (prognosis)Full recovery of hair is common.However, some people may have a poorer outcome, including those with:Alopecia areata that starts at a young ageEczema (atopic dermatitis)Long-term alopeciaWidespread or complete loss of scalp or body hair
Calling your health care providerCall your health care provider if you are concerned about hair loss.
ReferencesSperling LC, Sinclair RD, El Shabrawi-Caelen L. Alopecias. In: Bolognia JL, Jorizzo JL, Schaffer JV,et al, eds. Dermatology. 3rd ed. Philadelphia, Pa: Mosby Elsevier; 2012:chap 60.