Skin sensitivity to histolyn, spherulin, and PPD in the People's Republic of China.

One hundred one subjects living in northwest Hunan Province, People's Republic of China (PRC) were tested with histolyn, (Berkeley Biological Laboratories), spherulin (Berkeley Biological Laboratories), and tubersol (PPD 5 tuberculin units, Connaught Laboratories). Age of the tested subjects ranged from 16 to 58 years; 93 subjects were 22 years old or younger. Nine subjects reacted to histolyn with 5.0 mm or more induration, two subjects reacted to spherulin, and 34 subjects reacted to tubersol. One of the spherulin reactors also reacted to both histolyn and tubersol. The feasibility and advisability of doing a large-scale survey throughout the PRC seem clearly supported by this pilot project.