Keep a detailed symptom and food diary for 2 to 4 weeks
Track symptoms after high-histamine foods, alcohol, fermented foods, and leftovers
Try a short low-histamine elimination diet under medical guidance
Reintroduce foods one at a time and monitor symptoms
Ask a clinician about serum diamine oxidase (DAO) testing
Ask a clinician about plasma histamine testing
Ask a clinician about stool or urine histamine-related testing if available
Rule out food allergies with specific IgE testing or skin prick testing
Rule out mast cell disorders with appropriate medical evaluation
Rule out celiac disease, IBS, SIBO, and inflammatory bowel disease
Review medications that may affect histamine breakdown
Consider a supervised oral food challenge if recommended by a specialist
Seek evaluation from an allergist, gastroenterologist, or dietitian familiar with histamine intolerance