Alopecia areata causes unpredictable hair loss in 2% of population

Alopecia areata is an unpredictable autoimmune disease that affects approximately 2% of the global population. According to dermatologist Enilde Borges Costa of the Sociedade Brasileira de Dermatologia (SBD), the condition occurs when the body attacks the hair follicles, preventing healthy hair growth.

The disease can manifest in three primary ways: localized hair loss in small patches of the scalp, totalis (loss of all hair on the scalp), or universalis (loss of all body hair). Episodes are often cyclical, involving periods of hair regrowth followed by new shedding.

Diagnosis is currently conducted through clinical examination in a medical office, as there are no specific laboratory or imaging tests available to identify the condition. Doctors often look for hair that pulls out easily or the absence of hair in the beard, eyelashes, and eyebrows. While the condition has a genetic component and can be triggered by infections or other autoimmune issues, it is not classified as a psychological disease.