Introduction: Mucocutaneous complications or adverse events due to SARS-CoV-2 infection or vaccination have been well delineated in the literature, respectively. Most eruptions are considered mild and self-limiting; however, for the atypical cases with a tentative clinical diagnosis, performing a biopsy and histopathological assessment is pivotal to confirm the diagnosis and subsequently prescribe a more tailored treatment. Despite the diverse reporting of such incidents globally, most studies restrict the rate of biopsied cases to less than 15%. Case Presentations: This case series elucidates 20 patients referred to the tertiary dermatology clinic, including 14 COVID-19 infection-related eruptions such as lichen planus (LP), cutaneous vasculitis, pityriasis rosea (PR), discoid lupus erythematosus, guttate psoriasis, sarcoidosis, Raynaud's phenomenon, non-specific lesions resembling genital warts, Beau's line, and one severe case of purpura fulminans with a promising outcome. Moreover, we presented six vaccine-induced cases comprising LP, urticarial vasculitis, PR, parapsoriasis, and localized morphea. The diagnosis of all challenging cases has been proven by histopathological evaluation. We included pertaining anamnesis details of each patient and vivid classifying images to pinpoint the morphologic features of each condition. Discussion: In line with our previous studies, the vaccine-induced eruptions were less severe compared to infection-related complications of COVID-19 and are mostly controllable by antihistamines and corticosteroid administration. Therefore, reporting such events should not impede COVID-19 vaccination in the general population.
