Assessing cross-reactivity to neuromuscular blocking agents by skin and basophil activation tests in patients with neuromuscular blocking agent anaphylaxis

BACKGROUND

Following diagnosis of neuromuscular blocking agent (NMBA) anaphylaxis, identifying safe alternatives for subsequent anaesthesia is critical. A patient with anaphylaxis to one NMBA can also have an allergic reaction to other NMBAs (cross-reactivity). Whilst drug provocation testing is standard for identifying or excluding allergy, there is significant risk. In vitro, after an allergen activates basophils, basophils express surface activation markers that can be measured by basophil activation testing (BAT). We compared cross-reactivity between NMBAs assessed by BAT against that by skin testing.

METHODS

All patients attending an anaesthetic allergy clinic in Sydney, Australia between May 2017 and July 2018 diagnosed with NMBA anaphylaxis qualified for this study comparing intradermal skin tests and BAT with a panel of NMBAs (rocuronium, vecuronium, pancuronium, suxamethonium, cisatracurium).

RESULTS

Of the 61 patients participating, sensitisation on skin testing and on BAT completely matched in only nine patients (15%). Sensitisation was not in agreement for pancuronium, cisatracurium and rocuronium, but was in agreement for vecuronium and suxamethonium. Nine patients with negative skin tests subsequently tolerated cisatracurium, and one false positive on BAT to cisatracurium was detected.

CONCLUSIONS

The utility of BAT in identifying safe NMBAs for subsequent anaesthesia needs further evaluation. BAT detects a different cross-reactivity profile to skin tests. Negative skin testing and BAT might increase confidence in performing drug provocation testing, but this and follow-up of subsequent anaesthesia in our cohort is necessary to determine the clinical significance of BAT sensitisation.

A Case of Codeine Induced Anaphylaxis via Oral Route

Codeine is widely prescribed in clinical settings for the relief of pain and non-productive coughs. Common adverse drug reactions to codeine include constipation, euphoria, nausea, and drowsiness. However, there have been few reports of serious adverse reactions after codeine ingestion in adults. Here, we present a case of severe anaphylaxis after oral ingestion of a therapeutic dose of codeine. A 30-year-old Korean woman complained of the sudden onset of dyspnea, urticaria, chest tightness, and dizziness 10 minutes after taking a 10-mg dose of codeine to treat a chronic cough following a viral infection. She had previously experienced episodes of asthma exacerbation following upper respiratory infections, and had non-atopic rhinitis and a food allergy to seafood. A skin prick test showed a positive response to 1-10 mg/mL of codeine extract, with a mean wheal size of 3.5 mm, while negative results were obtained in 3 healthy adult controls. A basophil histamine release test showed a notable dose-dependent increase in histamine following serial incubations with codeine phosphate, while there were minimal changes in the healthy controls. Following a CYP2D6 genotype analysis, the patient was found to have the CYP2D6*1/*10 allele, indicating she was an intermediate metabolizer. An open label oral challenge test was positive. To the best of our knowledge, this is the first report of a patient presenting with severe anaphylaxis after the ingestion of a therapeutic dose of codeine, which may be mediated by the direct release of histamine by basophils following exposure to codeine.