Background  Alopecia areata (AA) is regarded to be mediated by autoimmune process, and manifests as patchy non-scarring hair loss with occult onset. Little is known about AA occurring later in life.

Objective  To define the characteristics of late-onset AA.

Methods  Patients with first onset of AA at age 50 years and above were retrospectively recruited from two separate institutes in southern and northern Taiwan. The onset age, patterns, severity, past history, serological findings and therapeutic responses were reviewed.

Results  Seventy-three AA patients were enrolled, including 49 females (67%) and 24 males (33%). The onset age ranged from 50–78 years with the median age of 57 years. Multifocal lesions (41%) constituted the most common pattern and 55% of the recruited patients had a hair loss of less than 10%. Seventeen patients (23%) had co-existent dermatological or systemic diseases while six patients (8%) had a history of malignancy. Among 27 patients (37%) with available laboratory data, positive anti-nuclear antibody, anti-microsomal antibody and anti-thyroglobulin antibody was demonstrated in 26%, 40% and 30% of them, respectively. Association with personal or family history of atopy was absent. In 15 patients of follow-up longer than 6 months, a complete hair regrowth was found in three patients with mild disease severity.

Conclusion  Late-onset AA is characterized by marked female predominance and milder disease activity with increasing age. The link to cancer in the old age remains to be determined. The influence of aging on the pathogenesis and prognosis of AA deserves further studies.