Shellfish Allergy Test London
This guide outlines shellfish allergy blood-test pathways, including tropomyosin cross-reactivity and the distinction between crustacean and mollusc reactions. Our service is CQC-registered and diagnostic-only: we provide nurse-led venous sample collection and laboratory reporting, while diagnosis and management remain with your GP or specialist.
Safety note
If severe breathing symptoms, throat swelling, collapse, or suspected anaphylaxis occur, call 999 immediately. Blood testing is not an emergency service.
Crustacean vs mollusc: why this matters
| Group | Examples | Clinical relevance |
|---|---|---|
| Crustaceans | Prawn, shrimp, crab, lobster | Common triggers in immediate IgE-mediated shellfish reactions |
| Molluscs | Mussel, clam, oyster, squid, octopus | Cross-reactivity may occur but is not universal across all patients |
Tropomyosin cross-reactivity
Tropomyosin is an important marker protein that can help explain cross-reactive patterns between some shellfish species. It may also overlap with sensitisation patterns seen in dust mite and cockroach allergy pathways.
Laboratory findings should always be interpreted with symptom timing, exposure pattern, and medical history by your GP or specialist.
Allergy Profile 6
Broad shellfish-focused IgE screening profile for structured pathway assessment.
View Profile 6 →Tropomyosin Test
Component-level support for cross-reactivity interpretation in selected shellfish cases.
View Tropomyosin Test →Frequently asked questions
What is the difference between crustacean and mollusc allergy?
Crustaceans include prawn, shrimp, crab and lobster, while molluscs include mussel, oyster, clam, squid and octopus. Cross-reactivity can occur, but not everyone reacts to both groups.
What is tropomyosin cross-reactivity?
Tropomyosin is a shared protein family found across multiple invertebrates. Sensitisation to tropomyosin may help explain reactions across some shellfish and can overlap with dust mite or cockroach sensitisation in selected patients.
Can this blood test diagnose shellfish allergy on its own?
No. Specific IgE results are supportive and should be interpreted with your reaction history by your GP or specialist. Our clinic provides nurse-led blood sample collection and laboratory reporting only.
What if I have severe symptoms after shellfish exposure?
If severe breathing difficulty, throat swelling, collapse, or suspected anaphylaxis occurs, call 999 immediately. Blood testing is not an emergency service.