Abstract
Skin testing for delayed hypersensitivity to tuberculin was performed in 36 patients with pneumonia associated with Mycoplasma pneumoniae infection. 22 of these patients had a negative tuberculin reaction when first tested. The tuberculin reaction was negative in 13 out of 16 cases tested during the first 2 weeks after onset of illness, in 6 out of 11 cases tested 15–28 days after onset of illness and in 3 out of 9 cases tested 29–45 days after clinical onset. In 19 patients with a negative tuberculin test in the early phase after onset of illness the test was repeated several weeks or months later. 16 of these cases had a positive tuberculin reaction at the later time period. Two of these cases showed prolonged tuberculin anergy for more than 5 months.