Allergy to sulfonamides

The combination of skin rash, swollen face, liver damage, lymph node enlargement, fever, and documented intake of drugs, which are known elicitors of drug rash with eosinophilia and systemic symptoms (DRESS), or drug-induced hepatitis in the last weeks prompted the suspicion of a severe drug allergy, possibly DRESS. [...]all drugs were stopped with the exception of prednisolone, doses of which were increased to 40 mg/d. Sulfanilamides are characterized by a sulfonamide moiety directly attached to a benzene ring, which carries an unsubstituted amine (-NH2) at the N4 position (Fig E2, A). Because immune reactions are directed to the structural component, patients with an allergy to a sulfanilamides might cross-react with other sulfanilamides with a different side chain but not with sulfonamides in general. In patients with severe nonimmediate reactions, such as the index patient, the T-cell immune system is massively activated, and these patients might temporarily react to many "innocuous" drugs with a flare-up. [...]it is our practice to reduce drug therapy in patients with DRESS as much as possible as long as activated lymphocytes are detectable in the circulation.