Alternaria scalp infection in a patient with alopecia areata. Coexistence or causative relationship?

Background: Alopecia areata is an autoimmune disease that is affecting anagen hair follicles. The triggers of autoimmunity in patients with alopecia areata remain unknown. Main observation: A 13-year-old boy developed multiple hairless patches of focal hair loss with typical clinical and trichoscopy features of alopecia areata. Mycology examination of the scalp hair and epidermal scrapings reveled massive growth of Alternaria chlamydospora. Conclusion: We hypothesize that fungal antigens (e.g. antigens involved in fungal melanin synthesis) may be possible triggers, contributing to autoimmune reactions in patients with alopecia areata. We discuss research data, which may indirectly support this hypothesis, however the concept has yet to be verified.