Histamine Symptom Questionnaire Rate each symptom based on how often and severely it occurs in the past 3–6 months. 0 = Never / No symptoms 1 = Rarely (once a month or less) 2 = Occasionally (several times a month) 3 = Frequently (several times a week) 4 = Very often (daily or almost daily) […]
Histamine Symptom Questionnaire