Bullous BCGitis a rare and uncommon complication of wart immunotherapy

Verrucae (warts) are the manifestation of infection caused by human papillomavirus (HPV). Approximately 65–78% of warts show spontaneous resolution within 2 years. No single therapy is uniformly effective for persistent warts; the wide variety of wart therapies is itself testimony to their inconsistent efficacy. Some warts might thus emerge recalcitrant. Immunotherapy is preferred for such warts which results in the resolution of all lesions. Various agents used for immunotherapy such as Mw (Mycobacterium indicus pranii), Bacillus Calmette-Guerin (BCG), purified protein tuberculin derivative (PPD), skin test antigens (mumps, Candida, and Trichophyton), and measles, mumps, and rubella (MMR) vaccine. BCG is one of the common agents among them. It has been postulated that it induces the Type I immune response along with a nonspecific reaction against viral antigens resulting in a therapeutic response at distant sites too. Though deemed safe, a number of complications may occur following BCG immunotherapy – local reactions, regional lymphadenitis, osteomyelitis, and disseminated infection in immunocompromised children, with lymphadenitis being the most common complication. Case report