The role of nontuberculous mycobacterial skin test antigens in the diagnosis of mycobacterial infections.

A retrospective study of 212 patients with mycobacterial infection was conducted to determine intradermal reactivity to five tuberculin units (TU) of purified protein derivative of Mycobacterium tuberculosis (PPD-S), and purified protein derivatives (PPDs) derived from non-tuberculous mycobacteria. PPDs B, Y, A, G, and F were used. The study included 138 patients with Mycobacterium tuberculosis infection, and 74 with proved nontuberculous mycobacterial infection. Eight possible patterns of skin test reactivity were discerned using PPD-S, PPD-B, and PPD-Y. In this population, selection of the largest skin test reaction within any one pattern correlated with the infecting organism in 87 per cent of the cases. Use of PPD-A, PPD-G, and PPD-F did not increase diagnostic capability. We conclude that differential skin testing with PPD-S, PPD-B and PPD-Y, is useful in the diagnosis of mycobacterial disease.