Penicillin allergy

When the causes of penicillin allergy are fully understood, they might well offer answers to a number of immunochemical and biologie conundrums. Supperficially, there is no mystery in the fact that penicillin causes allergy‐lots of simple substances cause allergy‐the mystery comes when one considers that, of the millions of people who receive penicillin, only a few, perhaps 3 per cent, develop allergy at one time or another, In most of these, the allergy is short‐lived or inconstant: A person who has reacted adversely to penicillin on one occasion may tolerate it subsequently, and vice versa. In a very small minority of allergie subjects, fewer than 0.1 per cent of the total, the dangerous state of anaphylaxis develops; to persons in this state, a milligram of penicillin, or less, can cause shock, collapse, and even death. One encounters individuals who are so sensitive that by merely handling a tablet of penicillin or by receiving a skin test dose of 10 to 100 units, they suffer an immediate reaction. Some subjects manifest this extreme sensitivity in the form of contact dermatitis, while in others the reaction may be remote from the site of contact or may be systemic. More so than with other specific allergies, the manifestations of penicillin allergy are extremely diverse; each of several organs may bear the shock, and the symptomatology of response is correspondingly varied (Table 1). To add to the mystery, it is on record that some persons (e.g., in 1944) who had never received penicillin have reacted violently to a first dose.