Cutaneous tuberculosis and pyoderma gangrenosum

A 59-year-old woman with multiple myeloma at stage IA exhibited recurrent pyoderma gangrenosum of 13 years’ duration. She also had a history of mitral regurgitation and cerebral infarction, but no significant family history was present. In September 1994, she noted a painful erythematous papule on her left foot, which was treated with a topical injection of triamcinolone. It responded well to this treatment at the time, but a similar eruption developed in the same place in February 1995, and enlarged to form an irregularly shaped, punched-out ulcer with surrounding infiltrative erythema despite topical treatment ( Fig. 1). Further, since November 1994, she had noted pain in the right dorsal foot. Figure 1. Necrotic ulcer with an elevated purulent border and pustules on the left foot Download figure to PowerPoint 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, cryoglobulin, Treponema pallidum hemagglutination (TPHA), stool test, and chest radiography. 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 salazosulfapyridine (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 tuberculosis 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) level and white blood cell (WBC) count became elevated, and bilateral multiple shadows were detected on chest roentgenography. Although ethambutol hydrochloride (EB) was added, the laboratory findings remained and the symptoms did 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. Foot roentgenography showed narrowed joint spaces and destruction of the cuneiform bones, suggesting bone and joint 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 disappeared, the ulcer on the left foot was epithelialized, and the swelling on the right foot with a pus-discharging fistula also disappeared. Figure 2. Dorsal aspect of the right foot with erythema, swelling, and pain Download figure to PowerPoint Figure 3. Biopsy of the ulcer showing lymphocyte infiltration with plasma cells and multinucleate giant cells Download figure to PowerPoint