Sporotrichoid nocardiosis caused by Nocardia nova in a patient infected with human immunodeficiency virus

Abstract

A23‐year‐old agricultural worker presented with multiple nodulo‐ulcerative lesions in a linear pattern along the right upper extremity. Two months prior, he had sustained an injury at the dorsal aspect of the base of the right thumb while working in the field. A nodular lesion appeared at the site after 3 weeks and subsequently suppurated, with discharge of purulent material and ulcer formation. Over the past 1 month, he had developed several other similar lesions along the right forearm up to the elbow. He was afebrile but complained of loss of weight in the recent past. He had a history of repeated unprotected sexual intercourse with commercial sex workers.General physical examination revealed a mild pallor. On local cutaneous examination, there was found to be an ulcer of about 2 cm × 2 cm at the base of the right thumb on the dorsal aspect (Fig. 1). The ulcer had a ragged margin with dirty slough at the floor, and the base was indurated and tender. On pressure, a purulent discharge was seen exuding from the surface. Similar nodulo‐ulcerative lesions of varying size were seen along the flexor aspect of the right forearm in a linear pattern (Fig. 2). Tender cord‐like structures were palpable between the lesions. The right epitrochlear and axillary lymph nodes were significantly enlarged and tender. Other cutaneous and systemic examinations were normal. A clinical diagnosis of nodular lymphangitis was made and the patient was investigated for etiological confirmation.Noduloulcerative lesion at the base of the thumbimageLesions in a sporotrichoid pattern over the forearmimageThe patient's hemoglobin was 10 mg dL−1, with hypochromic, microcytic peripheral blood. Erythrocyte sedimentation rate (ESR) was 100 mm in the first hour. Routine biochemical tests and chest X‐ray were within normal limits. A venereal disease research laboratory (VDRL) test was nonreactive. An enzyme‐linked immunosorbent assay (ELISA) for human immunodeficiency virus (HIV) was positive and the CD4+ T‐cell count was 550 cells/µL. A Gram‐stained smear from the discharge of a nodulo‐ulcerative lesion revealed numerous pus cells and a few irregularly stained, Gram‐positive, thin branching filaments. Modified Kinyoun staining demonstrated acid‐fast, branching filamentous structures (Fig. 3). Culture of the aspirated material from an unruptured nodule on Sabouraud's dextrose agar media grew small, whitish, dry, wrinkled colonies after 8 days.Photomicrograph showing thin branching filaments of Nocardia in the specimen of pus (modified Kinyoun stain, magnification ×100)imageBiochemically, the species showed urease positivity and reduced nitrate. Citrate utilization, gelatin liquefaction, casein hydrolysis and acetamide utilization tests were negative. An antibiogram showed sensitivity to erythromycin and broad‐spectrum cephalosporins. The species was identified as Nocardia nova on the basis of biochemical properties and the antibiogram. A skin biopsy was taken from the margin of an ulcer and histopathological examination revealed chronic granulomatous inflammation without demonstration of any organism.The patient was started on cotrimoxazole double strength (DS) tablets, twice daily. At follow‐up after 1 month, significant reductions in both inflammation and the size of the lesions were observed.The appearance of new nodular lesions was stopped. Follow‐up at 3 months showed complete healing of the nodulo‐ulcerative lesions, leaving few scars. The patient was advised to continue the same treatment for a further 3 months and has been monitored with regular follow‐up.