Histopathological Spectrum of Cutaneous Reactions following COVID-19 Vaccine - An Observational Study

Owing to the myriad clinical presentations of COVID-19 vaccine-induced adverse events, clinicopathological correlation is the key to understanding the underlying pathophysiology of these reactions. However, there is still a dearth of such systematic studies across a wide spectrum of vaccine reactions.

This study provides a clinical and histopathological correlation of COVID-19 vaccine-induced mucocutaneous reactions.

The study population included all the individuals developing any form of self-reported mucocutaneous adverse events within 4 weeks of receiving the COVID-19 vaccine. The clinical and histopathological features were recorded.

A total of 126 cases were identified. Seven histopathological patterns were recognized. The most common histopathological feature was spongiotic dermatitis, seen in all the patients with "vaccine-related eruption of papules and plaques" (VREPP). Other patterns included lichenoid or interface dermatitis, dermal hypersensitivity reaction, leukocytoclastic vasculitis, subepidermal blistering, psoriasiform hyperplasia, and dermal granulomatous reaction.

Owing to such myriad clinical presentations, utilizing a histopathological classification could ease categorizing the vaccine-induced mucocutaneous eruptions.