CIRCADIAN REACTIVITY RHYTHM OF HUMAN SKIN TO HOUSE DUST, PENICILLIN, AND HISTAMINE

Circadian rhythms characterize the extent of erythematous allergic response to fixed doses of house dust extract as well as penicillin. In the evening for diurnally active man, or, more generally, during the interval from 17.5 to 19.5 hours following the midpoint of the daily sleep span, a positive test may be more readily elicited than at other test times. Crests in the susceptibility rhythm to the allergens coincide roughly with the peaks of statistically significant changes characterizing the response of healthy subjects to a fixed dose of histamine and occur near the circadian trough in plasma corticosteroid levels, gauged in this study by urinary 17-hydroxycorticosteroid (17-OHCS) determinations. The findings, evaluated by electronic computer procedures, reveal the basic periodicity in man's susceptibility to a broad range of potentially harmful agents, while accounting on the practical side for some of the variability in cutaneous test results. © 1969.