BCG reactivation after COVID-19 vaccine: case report

BCG reactivation can occur in different contexts: associated with infectious conditions, immunosuppression, autoimmunity and post-vaccinations. Also, especially in children below of 5 years of age, should be valued as a finding present in about 50% of cases of Kawasaki disease. In this article, we report the first case published in the literature of a young adult patient, who manifested a reactivation of BCG after receiving the first dose of vaccine against COVID-19 (AztraZeneca/Oxford/Biomanguinhos). Within the first 24 hours after the administration of the vaccine, the patient developed high fever, sweating, local pain, diffuse myalgia and headache. After 2 days, erythema and induration at the site of the BCG vaccine scar began. she has how comorbidity to chronic spontaneous urticaria, but she was asymptomatic without crises for more than 1 year. The relevant family history is maternal death due to the complex syndrome of autoimmunity overlap (systemic lupus erythematosus, Sjögrens syndrome, and anti-phospholipid antibody). After being medicated with NSAID and moderate topical corticosteroid therapy potency for 3 days, there was complete resolution of BCG reactivation. The patient, after 3 months, received the 2nd dose of the vaccine and had no symptoms. It is believed that the reactivation of BCG occurs due to a cross-reaction mechanism between the individuals HSP, elicited as mediators of innate immunity against vaccine inflammation, with some epitopes of M. bovis. It is recommended that any immunosuppressive or autoimmune condition be investigated in patients that manifest BCG reactivation, especially in adults, in which Kawasaki disease is quite rare. Vaccines, including those against COVID-19, can also trigger of this immunological phenomenon still poorly understood.