IGHE and Allergy: The most common diagnostic tests performed were total serum IgE (83.5%), differential blood count (59.5%), serological tests (56.5%), allergy test (prick test) (56.0%), C-reactive protein ⁄ erythrocyte sedimentation rate (46.5%), autoimmune diagnostic (45.5%), thyroid hormones and autoantibodies (34.5%), and autologous serum skin test (13.5%).