Utility of polymerase chain reaction as a diagnostic tool in cutaneous tuberculosis

• Published in: Indian journal of dermatology, venereology, and leprology Vol. 69; no. 3; pp. 214 - 216
• Main Authors: PADMAVATHY, L, LAKSHMANA RAO, L, VELIATH, A. J
• Format: Journal Article
• Language: English
• Published: New Delhi Indian Association of Dermatologists, Venereologists and Leprologists 01-05-2003; Medknow Publications and Media Pvt. Ltd
• Subjects: Analysis; Bacterial diseases; Biological and medical sciences; Care and treatment; Dermatology; DNA; Genetic aspects; Health aspects; Human bacterial diseases; Infectious diseases; Medical sciences; Methods; Patients; Periodic health examinations; Physical diagnosis; Polymerase chain reaction; Skin; Tuberculosis; Tuberculosis and atypical mycobacterial infections; Asia; India; Human; Skin disease; Dermatology; Cutaneous tuberculosis; Mycobacterial infection; Infection; Polymerase chain reaction; Rapid diagnosis; Tuberculosis; Bacteriosis; Tropical medicine; Skin; Diagnosis; Molecular biology; PCR
• ISSN: 0378-6323; 0973-3922

Differentiation of cutaneous tuberculosis from other infective granulomas of the skin is difficult due to paucity of the organisms in tissue biopsies. Polymerase chain reaction (PCR) is a newer technique to identify the DNA of Mycobacterium tuberculosis in the tissues.
We examined the utility of PCR as a tool for rapid diagnosis of cutaneous tuberculosis especially in cases negative by ZN staining and culture.
Twenty five random skin biopsies from patients with various types of cutaneous tuberculosis were subjected to PCR.
An overall positivity of 64% was observed, which is comparable to other series. Seventy five percent of lupus vulgaris cases, 62.2% of tuberculosis verrucosa cutis and 50% of scrofuloderma cases showed PCR positivity.
Though useful, the cost and the technique involved limit the use of PCR in developing countries like ours.