Crustacean allergens cross-reactivity

Cross-reactivity between molluscan and crustacean shellfish species also occurs rafher frequently. Since tropomyosin is the major allergen in both molluscan and crustacean shellfish, fhe frequency of cross-reactions is not surprising. Allergy to crustacean shellfish is more frequenfly diagnosed than molluscan shellfish allergy (Hefle et ah, 2007). Many of fhese individuals may be at risk of reactions fo molluscan shellfish also. Appropriately, most individuals with either molluscan or crustacean shellfish allergy are advised to avoid all shellfish. 

CROSS-REACTIVITY OF CRUSTACEAN ALLERGENS 9.5.1 Within Crustaceans... 

Even though IgE cross-reactivity among crustaceans and mollusks are commonly reported until recently, limited work has been done on the molecular identity of these cross-reactive allergens. The amino acid sequence identity with shrimp tropomyosin is fairly low with 57% and 61% for mussels and abalone, respectively (Figure 9.1). The relationship of molecular cross-reactivity with clinical reactivity has however not been adequately defined. 

Clinical relevant cross-reactivity between crustacean and house dust mite allergens has been described (Witteman et al. 1994) and the term mite-crustaceans-mollusk-syndrome is sometimes used. The primary sensitization is believed mostly to be respiratory allergy to dust mites, which then sometimes causes food allergic reactions to crustaceans or mollusks in some individuals. However, there are also observations on allergy to mites or cockroaches possible occurring subsequent to... 

---