IGHE and urticaria: Patient characteristics included age, sex, serum total IgE concentration, serum specific IgE (sIgE) concentrations including <i>Dermatophagoides pteronyssinus</i> (D1) and <i>Dermatophagoides farina</i> (D2), comorbid conditions (asthma, urticaria, conjunctivitis, atopic dermatitis), and injection frequency.