Erythema Multiforme Reactions Following Pfizer/BioNTech (BNT162b2) and Oxford/AstraZeneca (chAdOx1-S) COVID-19 Vaccination: A Case Series: An International Journal of Medical Toxicology and Drug Experience

ABSTRACT

Introduction: Pfizer/BioNTech (BNT162b2) and Oxford/AstraZeneca (chAdOx1-S) COVID-19 vaccines were approved for emergency use. Clinical trials of both vaccines reported no safety concerns other than a few local and systemic reactions that resolved in few days for both vaccines. Cutaneous reactions to COVID-19 vaccination are generally minor and self-limited. The most common cutaneous reaction reported was a local injection-site reaction. Objective: Here we present 3 cases of erythema multiform following COVID-19 vaccination with positive rechallenge in 2 cases. Methods: Not applicable. Results: Case 1 A 51 year old woman with no past medical history presented with a macular, erythematous, round-shaped itchy rash on the hands, knees and soles. She denied having a neither recent illness nor sick contact. However, she received the first dose of the mRNA Pfizer/BioNTech (BNT162b2), 3 days earlier. Lesions disappeared in 7 days with local corticosteroid treatment. One month later and two days after receiving the second shot of the same vaccine, lesions reappeared and extended to upper members. Skin biopsy was compatible with erythema polymorph. Case 2 A 55 year old man with a past medical history of hypertension, presented 6 days following the 2nd shot of the mRNA Pfizer/ BioNTech (BNT162b2), vesicular eruptions on the upper and lower members. The outcome was favorable within 2 weeks under local corticosteroid. The patient reported that he had the same skin lesions in ankles and soles few days following the 1st shot of the same vaccine. Histological findings revealed an erythema polymorph. Case 3 A 57 year old woman with a medical history of hypertension and anxiety disorder presented with a worsening rash and fever for 6 days. The patient reported that she experienced fever, polyarthralgia and that she had received the second shot of Oxford/AstraZeneca (chAdOx1-S), the day before these symptoms appeared. On the physical examination, she had targetoid skin lesions over the trunk, on the ear, upper and lower members. Otherwise she had oral and genital mucosal ulcerations. A thoracic CT scan was performed because of the persistent fever and showed multiple enlarged lymph nodes, a layer of pericardial and plural effusion. A favorable outcome was observed in 3 weeks. Conclusion: Erythema multiform remains an exceptional COVID 19 vaccine adverse effect. Health care workers must be aware of this potential adverse effect or its recurrence and advise patients accordingly. Benefits of receiving a COVID 19 vaccine remains more important.