Allergic Sensitization in the Tropics: Unravelling Co-Sensitization Between Crustacean and Mites

Sahel Heidari^1,2,3Shaymaviswanathan Karnaneedi^1,2,3Elecia Johnston^1,2,3Emily Jerry^1,2,3Diamond Hira⁴Andreas Ludwig Lopata^1,2,3,5*

• ¹Molecular Allergy Research Laboratory, College of Science and Engineering, James Cook University, Townsville, Australia
• ²Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Australia
• ³Centre for Food and Allergy Research, Murdoch Children’s Research Institute, Melbourne, Australia
• ⁴Allergy Medical Centre, 126 Ross River Rd, Mundingburra QLD 4812, Australia, Townsville, Australia
• ⁵Tropical Futures Institute, James Cook University Singapore, 149 Sims Drive, 387380, Singapore, Singapore

Crustacean allergy, a common food allergy triggered by immune reactions to proteins in shrimp, lobster, and crab, involves over ten identified allergenic proteins and can lead to severe symptoms, including anaphylaxis. Shellfish-allergic individuals are often sensitized to house dust mites (HDM), yet the specific interrelationships remain unclear. This study analyzed 93 seafood-allergic individuals and selected 54 subjects with positive skin prick tests and/or ImmunoCAP-measured specific IgE to crustaceans. Allergy Explorer 2 (ALEX2) testing was subsequently performed for these individuals. The most reactive mite allergens (in total over 81%), included Der p 1, Der p 2, Der p 23, Der f 1, Der f 2, Gly d 2, and Lep d 2. Der p 23 alone was identified in over 61% of crustacean allergic subjects. Anaphylaxis was reported in 11 subjects, correlating strongly with IgE sensitization to tropomyosin (63.6%), but also to Lep d 2 and Der p 23 (both 54.5%). These findings stress the complex sensitization patterns in crustacean-mite allergic individuals in the tropics, highlighting both tropomyosin and non-tropomyosin cross-and co-reactivity. The significant IgE reactivity to Der p 23 and arginine kinase suggests the need for enhanced diagnostic approaches and further investigation into the clinical implications of these sensitization patterns in crustacean and mite sensitised individuals for improved allergy management.