Failure to demonstrate a refractory period following sublethal anaphylaxis under cover of antihistamine.

Attempts were made to desensitize guinea-pigs (which had been actively sensitized to bovine serum albumin) by injecting them 2 days before challenge with a near-lethal dose of the antigen under protection of antihistamine. No statistically significant desensitization occurred although there was a significant drop in the mean serum antibody titre as well as in the mean complement levels. However, antibody titre and sensitivity to anaphylaxis could not be correlated.