Abstract:

Objective To analyze the incidence of contact allergic reactions to ketoconazole shampoo and selenium sulfide shampoo in patients with androgenetic alopecia (AGA). Methods A retrospective analysis was conducted on 683 AGA patients. Based on medical records, dermoscopy findings, fungal examinations and patch test results, the number of patients with seborrheic dermatitis, Malassezia-positive cases and contact allergy to ketoconazole and selenium sulfide shampoos were recorded. Results The incidence of seborrheic dermatitis in AGA patients was 65.59%, and the Malassezia-positive rate was 42.02%. The allergy rate to ketoconazole shampoo in AGA patients was 34.70%, which was significantly higher than the 25.62% allergy rate to selenium sulfide shampoo (P<0.01). In AGA patients with concomitant seborrheic dermatitis and Malassezia positivity, the allergy rate to ketoconazole lotion was higher than that to selenium sulfide lotion (P<0.05). The positivity rate of Malassezia was 45.98% in seborrheic dermatitis patients, which was higher than that of the 34.47% in non-seborrheic dermatitis patients (P<0.01). Conclusion In patients with AGA, ketoconazole shampoo carries a higher allergy risk compared to selenium sulfide shampoo. Long-term use of antifungal shampoos should be avoided in patients with AGA and conduct patch tests for drug detection when necessary.

Key words: alopecia, dermatitis, seborrheic, disulfides, selenium, ketoconazole, dermatitis, contact