Fixed drug eruption after Pfizer-BioNTech COVID-19 vaccine: A case report

Rapidly progressing generalized bullous fixed drug eruption after the first dose of COVID-19 messenger RNA vaccination

Generalized bullous fixed drug eruption (GBFDE) is a rare type of life-threatening severe cutaneous adverse reaction that is considered a medical emergency because of its potential lethality. Currently, only a few cases of bullous adverse reactions have been reported after coronavirus disease 2019 (COVID-19) vaccination. We describe a patient with distinct clinical, histopathological, and immunological findings that are consistent with severe GBFDE, after Pfizer messenger RNA COVID-19 vaccination. An 83-year-old man presented with a fever and well-demarcated multiple erythematous patches that occurred only 4 h after receiving the first dose of COVID-19 Pfizer vaccination. Over the next few days, the patches became generalized and turned into blisters covering approximately 30% of the body surface. The patient was started on intravenous methylprednisolone and oral cyclosporine. There were no additional blistering lesions after 10 days of treatment, prompting a gradual dose reduction. Our case suggests that a stepwise vaccination adhering to the standard dosing schedule should be warranted with close monitoring for possible significant side effects.

Urticaria: A Narrative Overview of Differential Diagnosis

Urticaria is an inflammatory skin disorder that may occur in isolation or associated with angioedema and/or anaphylaxis. Clinically, it is characterized by the presence of smooth, erythematous or blanching, itchy swelling, called wheals or hives, which greatly vary in size and shape and last less than 24 h before fading to leave normal skin. Urticaria is the consequence of mast-cell degranulation that can be caused by immunological or non-immunological mechanisms. From a clinical point of view, many skin conditions can mimic urticaria and their recognition is mandatory for a correct management and therapeutic approach. We have reviewed all of the main relevant studies which addressed differential diagnosis of urticarial, published until December 2022. The National Library of Medicine PubMed database was used for the electronic research. The present review offers a clinical narrative overview, based on the available literature, of the principal skin disorders that can be misdiagnosed as urticaria (mainly autoinflammatory or autoimmune disorders, drug-induced reactions, and hyperproliferative diseases). The aim of this review is to provide clinicians a useful tool for correctly suspecting and identifying all of these conditions.

Generalized fixed drug eruption following Pfizer-BioNtech COVID-19 vaccination

Fixed drug eruption is a cutaneous drug reaction which recurs at the same site when the individual is exposed to the causative drug, characterized by single or multiple round sharply demarcated erythematous-to-violaceous patches. Here, we report a patient with generalized non-bullous fixed drug eruption following mRNA-based Pfizer-BioNTech COVID-19 vaccine.