Chou Cheng-cheng points out that patients must be absolutely certain that a given allergen is the one and only source of their allergy, and doctors will only consider immunotherapy if this allergen is hard to escape in the environment, the patient has at least a fairly heavy allergic reaction to it, and there are no drugs that can control it.
周正成指出，病人須確定過敏原而且是單一過敏原，這種過敏原在環境中不容易避免，過敏症狀屬中、重度，用藥無法控制或不宜長期用藥，醫生才會考慮為病人做減敏治療。