An unusual episode of lupus vulgaris masquerading as sporotrichosis

Case 1 A 24-year-old man presented with asymptomatic, gradually progressive plaques and nodules over the right knee extending to the thigh in a linear pattern of 3 months' duration. A year previously, he had been diagnosed wi th tuberculosis of the spine and had been advised to take antitubercular tr eatment; however, he chose to stop treatment on his own after 4 months of t herapy as his spinal condition improved with a marked decrease in pain. The re was no history of fever, systemic complaints, or any spinal or knee inju ry preceding the disease. His mother had received treatment for pulmonary t uberculosis 4 years previously. Dermatologic examination revealed well-defined, brownish papules, plaques, and nodules of variable sizes, ranging from 3 cm to 6 cm, present over the right knee and front of the thigh in a linear pattern. The lesions were sof t in consistency with "apple-jelly" nodules and the surrounding skin showed atrophic scarring (Fig. 1). All the hematologic and biochemical investigations were normal except for a n elevated erythrocyte sedimentation rate (ESR) (48 mm/1 h), Venereal disea se research laboratory (VDRL) test, enzyme-linked immunoabsorbent assay (EL ISA) for human immunodeficiency virus (HIV), and sputum examination for aci d-fast bacilli (AFB) were negative. Mantoux test with 1 tuberculin unit (TU ) of purified protein derivative-standard (PPD-S) showed an induration of 2 5 X 20 mm. Blood culture and culture of the tissue homogenate for Mycobacte rium tuberculosis, atypical mycobacteria, and fungal organisms revealed no growth. Slit skin smears from the plaque showed only lymphocytes and a few neutrophils, Immunoenzymatic test (ELISA) for antimycobacterial immunoglobu lin M (IgM) antibody against the A 60 antigen complex was strongly positive (> 1 : 200 U), Histopathologic examination revealed a hypertrophic epiderm is with noncaseating tuberculoid granulomas consisting of lymphohistiocytes , epithelioid cells, and Langhans' giant cells in the papillary and upper r eticular dermis (Fig. 2a,b). No AFB were detected. Polymerase chain reactio n (PCR) and guinea pig inoculation could not be performed due to a lack of facilities. Skiagrann of the chest was normal, although X-ray of the lumbosacral spine revealed bony destruction of the sacral foramina. A magnetic resonance imag e (MRI) in the sagittal and axial plane was suggestive of caries of the fif th lumbar and sacral vertebrae with a large presacral and anterior epidural collection (Fig. 3). Computed tomography (CT) scan-guided abscess drainage of the sacral region was performed and microscopic examination of the flui d revealed lymphocytes, polymorphs, macrophages, and a few AFB in a necroti c background, A diagnosis of lupus vulgaris (LV) of the right lower limb with Pott's spin e was made and the patient was administered antitubercular therapy consisti ng of rifampicin (450 mg), isoniazid (INH) (300 mg), ethambutol (800 mg), a nd pyrazinamide (1500 mg) daily for 2 months, followed by two drugs (rifamp icin and INH) for 4 months, With this, his cutaneous lesions resolved compl etely with cribriform scarring in 6 months. Treatment was continued for Pot t's spine for another 6 months as advised by the orthopedist. Case 2 A 30-year-old man presented with ulcerated plaques and nodules in a linear arrangement over the left foot extending to the lower leg of 5 month s' duration. A history of blunt trauma preceding the appearance of the lesions was prese nt. He had no systemic complaints and his family history was not contributo ry. Cutaneous examination revealed a soft, reddish-brown ulcerated plaque, 8 X 3 cm in size with "apple-jelly" nodules, on the dorsum of the left foot and linear nodular lesions over the leg (Fig. 4). There was no lymphadenopathy and his systemic examination was within normal limits, A bacillus Calmette -Guerin (BCG) scar was present over the left arm. His ESR was elevated (36 mm/1 h). Mantoux test with 1 TU PPD-S showed an in duration of 30 mm. HIV was nonreactive. Mycobacterial and fungal cultures f rom the tissue homogenate revealed no growth. Histopathologic: examination from the plaque revealed noncaseating tuberculoid granulomas in the papilla ry dermis suggestive of LV. Similar to the first case, he was also advised to take antitubercular therapy consisting of four drugs (INH, rifampicin, p yrazinamide, ethambutol) for 2 months, followed by two drugs (INH, rifampic in) for the next 4 months. The lesions resolved completely with puckered sc arring.