Incidence of various clinico-morphological variants of cutaneous tuberculosis and HIV concurrence: a study from the Indian subcontinent

BACKGROUND AND OBJECTIVES: There are few reports of cutaneous tuberculosis with immunosuppressed states such as HIV, use of immunosuppressants or malignancy. Diagnosis is thus difficult and despite scientific advances such as polymerase chain reaction, it is frequently missed. Although rare, given its worldwide prevalence and the rising incidence of HIV, it is important for clinicians to recognize the variants and promptly treat the patient. DESIGN AND SETTING: Retrospective study of all cases of cutaneous tuberculosis diagnosed from October 2007 to November 2009 at an outpatient clinic of a tertiary-care hospital in northern India. METHODS: We collected information on the clinical form of disease, histopathology and HIV concurrence rates and looked for differences in presentation between mmunocompetent and immunocompromised states. We also looked for differences and HIV concurrence between immunocompetent and immunocomprised patients. Diagnosis was based on clinical, histopathological and microbiological tests for tuberculosis and a test for HIV. RESULTS: The overall incidence of cutaneous tuberculosis was 0.7% (131 of 18720 outpatients). HIV concurrence was 9.1% (12 cases) of all cutaneous tuberculosis cases. Most common variants seen were scrofuloderma (36.5%), lupus vulgaris (31%), tuberculosis verruca cutis (12.9%), lichen scrofulosorum (11.4%), papulonecrotic tuberculids (3.8%), erythema nodosum (2.2%) and erythema induratum of Bazin (1.5%). CONCLUSIONS: Cutaneous tuberculosis rates were slightly higher in our study than in other studies from India. HIV co-infection rates were similar to those in other studies. Many atypical morphological forms and presentations were observed in HIV co-infected patients. Due to the varied clinical presentations, physician awareness and a high index of suspicion are necessary to diagnose cutaneous forms of tuberculosis.