Two for One: Tuberculid and Leukocytoclastic Vasculitis in an Adolescent

A 13-year-old girl with fevers, abdominal pain, and vomiting for 4 days presented with a full body pruritic rash that began in the axilla and spread rapidly to the rest of the body. She was recently diagnosed with tuberculosis and had been on rifampin, isoniazid, pyrazinamide and ethambutol (RIPE) therapy for 1 month to treat this infection, raising concern for a severe drug reaction. On exam, there were pink to hemorrhagic crusted papules diffusely on the body; two skin biopsies from the right ankle and right arm showed leukocytoclastic vasculitis and tuberculid pathologies, respectively. Tuberculids are a cutaneous form of tuberculosis that represent a hypersensitivity reaction to Mycobacterium tuberculosis or its antigens. These rashes can mimic other common diseases, and this case highlights the importance of obtaining histopathology early in the disease course for accurate and prompt diagnosis.