Transient Lymphocytic Colitis After SARS-CoV2 mRNA Vaccine

This is the first scientific report describing lymphocytic colitis after administration of the Pfizer severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) messenger RNA (mRNA) vaccine. The patient developed liquid stools, abdominal pain, and nausea within 24 hours of receiving the second dose. Symptoms were persistent for 3 months but improved 113 days after onset. Laboratory profiles and gastrointestinal polymerase chain reaction were normal. Esophagogastroduodenoscopy and colonoscopy performed 98 days after onset revealed patchy erythema in the descending colon and rectosigmoid. Mucosal evaluation revealed lymphocytic colitis. Review of the Vaccine Adverse Event Reporting System revealed 5 cases of microscopic colitis after the second mRNA dose. This report and Vaccine Adverse Event Reporting System cases suggest providers should consider microscopic colitis in the differential diagnosis of patients with severe, persistent diarrhea after the SARS-CoV2 mRNA vaccine.

Automated summary

This is the first scientific report to describe lymphocytic colitis as a potential adverse event following administration of the Pfizer mRNA vaccine for COVID-19. The patient experienced persistent symptoms including diarrhea, abdominal pain, and nausea for 3 months after receiving the second dose, but showed improvement after 113 days. The report also identified additional cases of microscopic colitis in the Vaccine Adverse Event Reporting System, suggesting that providers should consider this condition as a possible diagnosis for patients with severe, persistent diarrhea after the SARS-CoV2 mRNA vaccine.