Suppression of tuberculin reactivity during natural rubella. Observations with 54 patients

Fifty-four patients with previously positive tuberculin reactions were followed for tuberculin sensitivity, between the incubation period of natural rubella and the 40th day after the onset of rash. In many instances, tuberculin sensitivity was partially or completely depressed beginning in the incubation period and extending for up to 4 weeks after rash onset. Two of 3 cases of subclinical rubella infection also showed this phenomenon. The highest incidence of negative reactions was 83% in the first 3 days after rash onset. A few subjects had a larger skin reaction to tuberculin than the baseline reading during the 2 to 5 weeks after rash onset.