Papulonecrotic tuberculid caused by Bacille Calmette-Guerin vaccination requiring no antitubercular agents

This paper describes a case of papulonecrotic tuberculid after Bacille Calmette-Guerin (BCG) vaccination. A 6-month-old boy was seen in our emergency room with a fever and erythematous papular. He received BCG vaccination at the age of 5 months and there were no systemic problems after the vaccination. There were no abnormal physical findings except for skin lesions and fever. Histopathologically, the lesion was associated with pyogenic granulomatous inflammation and fibrosis, with multiple instances of vascularization and infiltration of various inflammatory cells. Acid-fast stain, culture,and polymerase chain reaction for tuberculous bacillus DNA of the papulonecrotic skin lesions were negative. He was diagnosed papulonecrotic tuberculid caused by BCG vaccination. The fever lasted 10 days, and all lesions healed spontaneously in 2 months. Papulonecrotic tuberculid is a vasculitis caused by an allergic reaction to an internal focus of Mycobacterium tuberculosis or its metabolites. The appearance of an unexplained skin rash may cause parental anxiety, nevertheless the disease may require no treatment unless the patient is immunocompromised. It is necessary to improve awareness regarding the disease as a side effect of BCG vaccination.