Specific exclusion criteria included a diagnosis or a history suggestive of a severe non-IgE mediated drug allergy including severe cutaneous adverse reactions (SCARs), an active infection at time of evaluation, uncontrolled asthma, and any concurrent medication intake that could interfere with skin testing (anti-histamines, omalizumab) or place the patient at risk during challenge (beta-blockers). The gene discussed is IGHE; the disease is Allergy.