Allergy and clinical immunology department is a division that treats and researches diseases that cause hypersensitivity reaction arising from excessive immune reaction against external materials. Many external materials that we come in contact with from our surroundings apply as allergen (causative materials for allergy), causing various allergic diseases. Dust mites, pollens, molds, food and drugs are allergen which can cause all allergic diseases. In order to prevent and treat allergic diseases, it is important to find the cause of allergen. Allergen which is the cause of allergy must be removed from the surroundings and by selecting and administering appropriate medicine. If the medicine is efficacious, immunity treatment can begin to effectively treat it. However, because allergic diseases are accompanied by various symptoms which is not restricted to a certain body part, a lot of patients go through difficult times because they have not been diagnosed and treated accurately. Chosun University Hospital’s allergy and clinica immunology department performs various specialized examinations in order to identify the accurate cause and to make diagnosis.