# 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

## TL;DR

A patient had an allergic reaction during surgery to Patent Blue V dye and possibly suxamethonium, with follow-up showing sensitivity to both and cross-sensitivity to methylene blue.

## Contribution

This case highlights cross-sensitivity between Patent Blue V dye, suxamethonium, and methylene blue, emphasizing the need for thorough allergy follow-up.

## Key findings

- The patient showed sensitivity to Patent Blue V dye and suxamethonium.
- Cross-sensitivity to methylene blue was confirmed via intradermal testing.
- The reaction's bi-phasic nature may be explained by sensitization to multiple agents.

## Abstract

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.