Skin reactions to intradermal neuromuscular blocking agent injections: a randomized multicenter trial in healthy volunteers.

BACKGROUND: Numerous reports confirm the performance of intradermal tests for the diagnosis of anaphylaxis during anesthesia; however, there is controversy over their diagnostic value regarding the newer neuromuscular blocking agents (NMBAs). METHODS: One hundred eleven healthy volunteers were randomly assigned to receive intradermal injections of two NMBAs, at five increasing concentrations. A concentration was considered as a reactive concentration when it led to a positive reaction in more than 5% of the subjects. These concentrations were compared with the maximal concentration recommended for the diagnosis of sensitization to NMBAs. RESULTS: The maximal nonreactive concentrations were 10 m for suxamethonium; 10 m for pancuronium, vecuronium, rocuronium, and cisatracurium; and 10 m for atracurium and mivacurium. Except for mivacurium, these nonreactive concentrations were close to the maximal concentrations used for the diagnosis of sensitization against NMBAs. For mivacurium, the nonreactive concentrations were higher than the maximal concentration currently recommended in clinical practice. CONCLUSION: The aminosteroidal NMBAs pancuronium, vecuronium, and rocuronium and the benzylisoquinoline cisatracurium have a similar potency to induce a nonspecific skin reactivity. If the criteria for positivity and the maximal concentrations of the commercially available compounds recommended by French practice guidelines are used, the risk of false-positive results is limited, and only minor modifications of these recommendations could be suggested. A slight reduction in the maximal concentration used for rocuronium from 1:100 to 1:200 and an increase from 1:1,000 to 1:200 for mivacurium can be proposed.

[Cross reactivity of food allergens and its clinical relevance]. / Allergies alimentaires croisées: quelles nouveautés ?

Cross-reactions between food allergens and other allergens are a major focus of interest. They include cross-allergies between Betulaceae and Compositae pollen, and also between fruits and vegetables (Prunoideae and Apiaceae). Cross-allergies between animal allergens include mites, cockroaches and crustaceans, milk and meat, animal epithelia, meat and egg. Cross-reactivity results from homology between protein sequences, and is highly likely when this homology reaches about 70%. Phylogenetically similar proteins occur in all species and are known as pan allergens. Profilins, Bet v1 homologues, and lipid transfer proteins have varying degrees of clinical relevance. The involvement of cross-reactivity in the persistence of sensitization and in allergic disorders is unclear. The consequences of cross-reactivity during specific immunotherapy with total allergenic extracts are random. Interpretation of biological tests of IgE binding is also biased by cross-reactivity. The use of panels of major recombinant allergens should help to identify specific sensitization profiles as well as clinically relevant sensitization. Cross-reactivity between epitopes of inhalants and of food allergens may perpetuate and intensify allergic disorders. The consequences of cross-reactivity between allergens and autologous proteins are unknown.