DRD2 and urticaria: Several participants also reported allergies other than AR; a total of 49% of the cohort reported a history of skin allergies (eczema, hand dermatitis, urticaria, and itchy rash), 27% also reported a history of food allergy, and 11% also reported a history of drug allergy (including Codeine [opioid], antibiotics, and metoclopramide [dopamine D2 receptor antagonist/5‐HT3 receptor antagonist/5‐HT4 receptor agonist]).