Erythema multiforme from betalactams with positive cutaneous tests

We report the case of a woman who after taking ampicillin and amoxicillin developed two severe cutaneous reactions with generalized erythema and maculopapular rash, which later turned into blisters with subsequent desquamation. She was clinically diagnosed with erythema multiforme syndrome after positive delayed cutaneous tests with benzylpenicillin, amoxicillin and ampicillin allowed for a more specific diagnosis. There are very few references to patients with drug reactions to betalactams who have positive skin prick or intradermal test but show delayed hypersensitivity, as was the case in our patient.