Anaphylaxis to Patent Blue V Dye With Clinical Deterioration Following Administration of Suxamethonium and Sensitisation on Skin Testing to Methylene Blue, Patent Blue V Dye and Suxamethonium.

Neuromuscular blocking drugs (NMBAs) and Patent Blue V dye sodium salt 2.5% (Guerbet, Roissy, France) are frequently implicated in perioperative allergic immunoglobulin E (IgE) mediated anaphylaxis. Most cases of anaphylaxis during surgery occur at induction of anaesthesia, although reactions to vital dyes injected into soft tissues often show a delayed onset. We present the case of a female in her 60s who suffered perioperative anaphylaxis to Patent Blue V dye and possibly suxamethonium during oncological breast surgery. Allergy clinic follow-up confirmed sensitivity to both drugs which may explain the unusual bi-phasic nature of the reaction. Intradermal testing also found cross-sensitivity to methylene blue, but not to other common allergens or NMBAs. This case demonstrates the importance of thorough post-anaphylaxis follow-up and raises the possibility of cross-sensitivity between unrelated compounds.