Mantoux test and its interpretation

Abstract

The tuberculin skin test is one of the few investigations dating from the 19th century that are still widely used as an important test for diagnosing tuberculosis. Though very commonly used by physicians worldwide its interpretation always remains difficult and controversial. Various factors like age, immunological status coexisting illness etc influence its outcome, so also its interpretation. Utmost care is required while interpreting the result and giving an opinion. This article has been written with the purpose of elucidating the performance and interpretation of the standard tuberculin test.

Probable hepatic tuberculosis masquerading as Klatskin tumour in an immunocompetent patient

“…The reaction is read by measuring the diameter of the induration across the forearm in millimeters. Various factors in the host and inherent in the test lower its specificity and sensitivity 8. Hence, the results of this test must be interpreted carefully, along with the patient's clinical context.…”

“…A low-risk patient must have a larger induration size for a positive result than a high-risk patient. High-risk groups include immunosuppression (HIV, organ transplant, long-term corticosteroid therapy and end-stage renal failure), recent contacts of active tuberculosis cases and persons with nodular or fibrotic changes on chest radiograph consistent with old healed TB 8. Some patients may react to the Mantoux test even though they are not infected with M tuberculosis .…”

Co-Expression of hbha and mtb32C Genes from Mycobacterium tuberculosis H37Rv in a Prokaryotic System

“…Other limitations are as follows, a need for a patient visit after PPD administration, inter-observer variability and disability in differentiating recent from latent infection. As a result, TST is not considered as a gold standard test (27,28).…”

10.7241/ourd.20174.147

“…The patient did follow up once after the biopsy for the report following that he was lost to follow-up. test, consequently, the test may be positive in an un-infected child and negative in a patient with full blown TB [1].…”

“…Features of reaction include erythema and induration at the injection site. The amount of induration is measured transversely to the long axis of the forearm and is recorded in millimeters [1]. This is a form of delayed-type hypersensitivity reaction.…”