Histologic examination showed psoriasiform hyperplasia with confluent parakeratosis. Within the dermis were granulomatous infiltrates composed of histiocytes, epithelioid cells, and Langhans giant cells mixed with aggregates of neutrophils and perivascular lymphocytic inflammation.
Findings of polymerase chain reaction testing for Mycobacterium tuberculosis DNA from the skin biopsy specimen were positive. The results of acid-fast bacilli culture from the skin biopsy specimen and the Mantoux test were negative. Chest radiography did not show any focal lung infiltrates or fibrosis. Findings of proctoscopy and computed tomography of the abdomen and pelvis were normal. Analysis of sputum smears and cultures found no acid-fast bacilli.