Crab Allergy Blood Test in Arizona

What this test measures

This test measures allergen-specific immunoglobulin E against crab proteins. Shellfish allergy is common in adults and often persists, and crustaceans such as crab, shrimp, and lobster share the protein tropomyosin, a frequent target of allergic antibodies. Reactions can range from mild itching to more serious symptoms, so assessment should be handled carefully. The immunoassay reports crab-specific antibody levels and an IgE class.

A blood sample is collected by venipuncture at a partner laboratory and analyzed with an immunoassay. Results are reported in kilounits per liter, and total IgE and eosinophil counts may be included for context. Because tropomyosin is shared across crustaceans, a crab result may be accompanied by reactivity to shrimp or lobster. Mollusks such as clams are a separate group, so cross-reactivity between the two groups varies.

People order this test after a suspected reaction to crab or as part of a broader shellfish evaluation. It can help guide dietary decisions and allergy planning with a clinician. The test identifies sensitization rather than confirming a clinical allergy, and it cannot predict reaction severity, so a qualified healthcare provider should interpret the findings.