The clinical and pathologic spectrum of mucocutaneous reactions after COVID-19 vaccinations in three tertiary referral centers of northern Italy

Adverse cutaneous reactions after COVID-19 vaccinations have increased, highlighting not only how SARS-CoV-2 infection but also COVID-19 vaccines may induce adverse cutaneous manifestations. We evaluated the clinical and pathologic spectrum of mucocutaneous reactions after COVID-19 vaccinations, observed consecutively within three large tertiary centers of the Metropolitan City of Milan (Lombardy), comparing our results with the currently available literature. We retrospectively reviewed medical records and skin biopsies of patients diagnosed with mucocutaneous adverse events after COVID-19 vaccinations and followed at three Italian tertiary referral centers in the Metropolitan City of Milan. One hundred twelve patients (77 women and 35 men (112 total); median age, 60 years) have been included in the present study; a cutaneous biopsy was performed in 41 cases (36%). The trunk and arms were the most involved anatomic areas. Autoimmune reactions after COVID-19 vaccinations, urticaria, morbilliform eruptions, and eczematous dermatitis have been the most commonly diagnosed disorders. Compared to the currently available literature, we performed many more histologic examinations, allowing us to make more precise diagnoses. Most of the cutaneous reactions were self-healing and/or responded to topical and systemic steroids and systemic antihistamines, thus not discouraging the general population from carrying out vaccinations, which currently have a good safety profile.