Related Experiment Video
Updated: Sep 27, 2025

Author Spotlight: Advancing Immune Monitoring in Critical Care Patients Using Whole Blood Assays
Published on: September 20, 2024
Atypical Presentation of Erythema Nodosum Following Pfizer-BioNTech COVID-19 Vaccine
Nasser Alzoabi1, Jamal Alqahtani1, Bader Algamdi1
1Department of Dermatology, College of Medicine, Imam Abdulrahman bin Faisal University, Dammam, Saudi Arabia.
Background:
Erythema nodosum (EN) is a common form of panniculitis that could be triggered by numerous conditions including infectious and non-infectious conditions. So far, few cases of EN caused by COVID-19 vaccine had been reported.
Case Report:
We report a case of atypical presentation of EN mimicking cellulitis in a patient who received the first dose of the Pfizer-BioNTech COVID-19 vaccine. A 38-year-old healthy woman who developed painful swelling on the left leg one week after receiving the first dose of Pfizer-BioNTech COVID-19 vaccine. Skin biopsy was revealed septal panniculitis. Due to the temporal association and the absence of other identifiable causes, Pfizer-BioNTech COVID-19 vaccine-related EN would be the most likely explanation.
Conclusion:
COVID-19 vaccines could be associated with rare side effects that should be reported for a better understanding of related outcomes of COVID-19 vaccination. This case was reported to keep in mind that EN can have atypical presentation as a rare side effect of COVID-19 vaccines.
Related Concept Videos
Endocarditis II: Clinical Features of Infective Endocarditis
Myocarditis II: Clinical Features and Diagnostic Tests
Myocarditis I: Introduction
Myocarditis III: Medical Management
Cross-reactivity
Pericarditis II: Clinical Features and Diagnostic Tests

