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

Area of Science:

• Dermatology
• Autoimmune Blistering Diseases

Background:

• The Koebner phenomenon, where skin trauma induces lesions in patients with pre-existing skin conditions, is well-documented.
• While reported in psoriasis, its association with pemphigus, particularly triggered by face masks during the COVID-19 pandemic, is less understood.

Observation:

• Two cases of pemphigus (one vulgaris, one vegetans) presented with new, persistent lesions on the nose.
• These lesions appeared after prolonged face mask use and were located in areas of maximal mask irritation.

Findings:

• The development of new pemphigus lesions correlated with face mask usage.
• Nasal lesions persisted despite treatment that improved other skin manifestations, suggesting a localized Koebner phenomenon.

Implications:

• Face masks can act as a trigger for the Koebner phenomenon in pemphigus patients.
• This highlights the importance of considering minor trauma from medical devices in the management of autoimmune blistering diseases.