Mask-induced Koebner Phenomenon in Pemphigus Patients During COVID-19 Pandemic.

Koebner phenomenon of skin diseases due to face masks have been reported since COVID-19 pandemic, especially in psoriasis patients. Although there are reports on Koebner phenomenon in pemphigus patients in the literature, pemphigus lesions triggered by face masks have not been described previously. Herein, we report one case of pemphigus vulgaris and one case of pemphigus vegetans with new and persistent lesions on the nose following prolonged use of face masks. Both cases had persistent pemphigus lesions on their noses where face masks irritated the most. The development of lesions after the use of masks and the persistence of nasal lesions despite the improvement of other skin lesions with the treatment in both cases, suggested that minor traumas due to the use of masks played a role in the formation of lesions.