Severe cutaneous adverse reactions (SCAR’s) are a heterogeneous group of delayed T cell mediated hypersensitivity reactions, which include Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS) and acute generalized exanthematous pustulosis (AGEP) ( 1). Based on our experience we provide clinicians with a practical algorithm for testing for cross-reactivity in non-SJS/TEN severe cutaneous adverse reactions.
Penicillin cross reactivity series#
In our case series cross-reactivity or co-reactivity commonly occurred among the beta-lactam antibiotic class, however further research is required to investigate and understand patterns of cross-reactivity. We assessed patients presenting with non-SJS/TEN severe cutaneous adverse reactions to a tertiary hospital drug allergy clinic. Historically, these reactions were considered to be specific to the inciting antibiotic and therefore likely to have minimal cross-reactivity. The underlying immunopathogenesis of these reactions is not completely understood but involves interactions between small molecule drugs, T cells and HLA molecules.