Peanut allergy blood test: what to know

A positive result can indicate sensitisation, which is different from confirmed clinical allergy. A negative result lowers concern but may not settle every case. Your clinician considers the timing and type of symptoms, the food amount, other ingredients, and any history of reactions. If uncertainty remains, an allergist may discuss supervised testing; never test a suspected allergen at home.

Tell the clinician about previous reactions, eczema, asthma, medicines, and foods that cause symptoms. Do not deliberately eat peanut to prepare for the test. Until the assessment is complete, follow the avoidance advice you were given and check labels for peanut and possible cross-contact. Ask for a written plan explaining what to do if exposure occurs.

After possible peanut exposure, sudden trouble breathing, throat or tongue swelling, widespread hives, repeated vomiting, dizziness, collapse, or marked weakness may signal anaphylaxis. Use your prescribed emergency medicine if instructed and call emergency services immediately. Do not wait for a blood-test result or rely on an antihistamine for severe breathing or circulation symptoms.

Ask what the result means in relation to your actual reactions, whether another allergy test is useful, and whether you need an emergency action plan. Discuss peanut avoidance, label reading, school or workplace precautions, and how asthma could affect emergency planning.