Papulonecrotic tuberculid secondary to Mycobacterium bovis.

A patient with papulonecrotic tuberculid had a pruritic papular eruption associated with constitutional symptoms. The eruption flared whenever the patient received low doses of prednisone to control symptoms of temporal arteritis. A cervical lymph node biopsy specimen demonstrated acid-fast bacilli, and Mycobacterium bovis grew on the cultures. The eruption cleared completely with antituberculous therapy. This case demonstrated the clinicopathologic findings compatible with a diagnosis of papulonecrotic tuberculid. Skepticism regarding the existence of papulonecrotic tuberculid is probably a result of the current decreased prevalence of untreated tuberculosis, and the subsequently increased rarity of this entity.