Cutaneous tuberculosis and pyoderma gangrenosum

A 59-year-old woman with multiple myeloma at stage IA exhibited recurrent p yoderma gangrenosum of 13 years' duration. She also had a history of mitral regurgitation and cerebral infarction, but no significant family history w as present. In September 1994, she noted a painful erythematous papule on h er left foot, which was treated with a topical injection of triamcinolone. It responded well to this treatment at the time, but a similar eruption dev eloped in the same place in February 1995, and enlarged to form an irregula rly shaped, punched-out ulcer with surrounding infiltrative erythema despit e topical treatment (Fig. 1). Further, since November 1994, she had noted p ain in the right dorsal foot. The laboratory findings showed an elevated concentration of immunoglobulin A (IgA) (607 mg/dL) in the serum and the presence of Bence-Jones protein in the urine. The following examinations revealed normal or negative values: full blood cell count, rheumatoid factor, complement components, cryoglobul in, Treponema pallidum hemagglutination (TPHA), stool test, and chest radio graphy. The histology of a biopsy specimen from the elevated border of the lesion showed predominant neutrophilic infiltrates in the upper dermis and a diagnosis of recurrent pyoderma gangrenosum was made. Treatment with sala zosulfapyridine (2 mg/day) was started. Two weeks of therapy resulted in a poor response, and so systemic administration of prednisone (30 mg/day) was started. As the bacterial culture examination revealed Mycobacterium tuber culosis growth from the surface exudate of the ulcer and a tuberculin test was strongly positive, rifampicin (RFP) and isoniazid (INH) were added. In spite of these therapies, fever increased, the C-reactive protein (CRP) lev el and white blood cell (WBC) count became elevated, and bilateral multiple shadows were detected on chest roentgenography. Although ethambutol hydroc hloride (EB) was added, the laboratory findings remained and the symptoms d id not sufficiently respond. Furthermore, she noted a painful, erythematous and edematous swelling on the dorsum of her right foot (Fig. 2), where an aspiration test disclosed caseous material in the pus. M, tuberculosis was also positively cultured from the pus. Fool roentgenography showed narrowed joint spaces and destruction of the cuneiform bones, suggesting bone and j oint tuberculosis. An additional biopsy specimen from the ulcer of the left foot showed a granulomatous infiltration surrounded by multinucleate giant cells (Fig. 3), and cutaneous tuberculosis was confirmed by a niacin test; polymerase chain reaction was positive. After administration of RFP 0.45 g /day, INH 0.3 g/day, and EB 0.75 g/day for 15 months, the lung shadow disap peared, the ulcer on the left foot was epithelialized, and the swelling on the right foot with a pus-discharging fistula also disappeared.