Persistent cutaneous cellular immune responsiveness in a nursing home population.

Mantoux-type skin tests were applied to 29 elderly residents of an intermediate care floor of a nursing home. Eight antigens were used with each resident, and the size of the reactions was measured at 6, 24, 48, and 72 hours. All but one resident had at least one response greater than or equal to 3 mm at 48 or 72 hours, and most had more than one response of that size. At 48 compared with 72 hours, there was one more responder and the mean size of the reactions to each antigen was greatest. However, there were two responders at 72 hours who did not react at 48 hours, and the total number of reactions in the group was greater at the later reading. Only one resident did not produce any response at either 48 or 74 hours. The minimum number of antigens needed to identify all responsive subjects was five (PPD-Avian, coccidioidin, histoplasmin, streptokinase-streptodornase, and trychophytin). The purified protein derivative of tuberculin skin test was repeated on subjects who had an initial response less than 10 mm, and one increase of more than 6 mm was observed in a resident who was initially unresponsive to that antigen.