Is IgE useful for allergy?

IgE (Immunoglobulin E) is a key biomarker for immediate-type (Type I) allergic reactions. Specific IgE against allergens (e.g., pollen, foods) has good clinical validity and is used in routine diagnostics. However, interpretation is not trivial: positive specific IgE indicates sensitization, not necessarily clinical allergy. Total IgE is non-specific and can be elevated in parasitic infections or certain immunodeficiencies. Evidence for using specific IgE in allergy diagnosis is strong (human-strong), but results must be correlated with history and possibly challenge tests. A standalone IgE test without clinical context is insufficient. Caveat: false positives are common, especially for food allergies. MyBody-X tests can measure IgE, but interpretation should be done by an allergist. Overall, IgE is useful but not a standalone diagnostic proof.