Pathophysiology continued:

Prior to 1970, PCN preparations were often contaminated with trace quanities of macromolecules and drug polymers which increased the frequency of allergic reactions. Recent “purified” PCNs have reduced these reactions.

Rashes are common in a variety of infections. (HIV, Hep B, Coxsackie virus, Echo virus, etc.)

Therefore, patients with infections who take PCN and develop a rash should not automatically be labeled with PCN allergy.

Prior to 1970, PCN preparations were often contaminated with trace quanities of macromolecules and drug polymers which increased the frequency of allergic reactions. Recent “purified” PCNs have reduced these reactions.