Alopesi

Alopesi, or alopecia, is the partial or complete loss of hair from areas of the body that normally grow hair, most commonly the scalp. The condition can be temporary or permanent and may affect appearance and mood. Hair loss can be localized or diffuse and may involve one or more regions.

The term covers several distinct conditions. Non-scarring (cicatricial) alopecia does not destroy the hair follicle, while scarring alopecia involves permanent follicle destruction. Common forms include alopecia areata (patchy, autoimmune), androgenetic alopecia (pattern hair loss linked to genetics and hormones), telogen effluvium (diffuse shedding after stress, illness, or hormonal changes), and traction alopecia (hair loss from prolonged tension or harsh hairstyles). Scarring alopecias arise from inflammatory skin diseases such as lichen planopilaris or discoid lupus, which can permanently affect follicles.

Causes and risk factors vary by type. A genetic predisposition and autoimmune processes underlie many cases, while hormonal factors, thyroid disease, iron deficiency, and other nutritional deficiencies can contribute. Medications, infections, physical or chemical damage to the scalp, and chronic inflammation are additional contributors. Risk factors include age, sex, ethnicity, and a history of autoimmune disease or family history of hair loss.

Diagnosis typically involves clinical examination and history, a hair pull test, dermoscopy, and sometimes scalp biopsy. Blood tests may be used to evaluate thyroid function, iron status, and other conditions that can cause shedding.

Treatment depends on the type and extent of hair loss. Androgenetic alopecia may respond to topical minoxidil, and for men, oral finasteride or dutasteride. Alopecia areata is often treated with intralesional or topical corticosteroids, and sometimes immunotherapy or JAK inhibitors. Traction and telogen effluvium address underlying causes or remove contributing factors. Scarring alopecias focus on controlling inflammation; the resulting hair loss is often irreversible. Prognosis varies, with some forms regrowing hair and others becoming chronic or permanent.