Mycobacterial lymphadenitis in Western Australia.

The records of 172 patients with culture-positive mycobacterial lymphadenitis in Western Australia between January 1972 and December 1989 inclusive have been reviewed. Of the 118 children under 7 years of age, the disease was caused by M. tuberculosis in 4%, the M. avium complex in 74% and M. scrofulaceum in 20%, whereas in the 54 adults aged 15 years and over, the same organisms were responsible for 89%, 2% and 4% respectively of their diseases. Tuberculous (TBC) lymphadenitis affected mainly adult Asian migrants (71%), while non-tuberculous mycobacterial (NTM) lymphadenitis predominantly affected non-Aboriginal Australian children (92%). The two conditions differed significantly in their distribution of disease in the lymph nodes (P < 0.001). Patients with the TBC disease had a longer (P < 0.001) duration of symptoms before diagnosis but less common (P < 0.02) local complications at presentation than those with the NTM disease. The response of TBC lymphadenitis to medical treatment was excellent with no failure or relapse in the 43 patients followed up to 12 months. Total excision was curative for NTM lymphadenitis although in 10% a second excision was needed because of relapse or residual disease. In a selected group of children, the double Mantoux test was shown to have a 79% sensitivity and a 69% specificity in the diagnosis of the NTM disease. Over the last decade, the prevalence of NTM lymphadenitis in Western Australia decreased while that of TBC lymphadenitis remained steady.