People in the United States report allergy to penicillin more commonly than any other medication. However, not all of them are truly sensitive to that drug. The reports suggest that a tenth of the general population in that country cannot tolerate this well-known antibiotic, but clinical observation shows that hypersensitivity is less present than that [1, 2].
In fact, those who are really allergic to it eventually lose their sensitivity with the passage of time . Within five years of an immediate hypersensitivity immune response from penicillin, nearly half of these clients will be able to tolerate administration of the antibiotic. Ten years after this type of immune response to that medication, four-fifths will be able to receive it without the occurrence of an allergic reaction .