Correct nebulization of children is generally not harmful, but if the nebulization method is not appropriate or allergic to drugs may lead to allergic reactions, nasal mucous membrane damage, pulmonary edema and so on. 1. Allergic reaction: nebulization generally use hormone drugs, sometimes may also need to cooperate with the bronchodilator drugs, if the child is allergic to these drugs, it may lead to respiratory difficulties, asthma, respiratory spasm, skin itching and other allergic symptoms. 2. Nasal mucous membrane damage: when nebulizing, if the speed is too fast, the high-speed oxygen flow may cause damage to the nasal mucous membrane, resulting in nasal mucous membrane ulceration, bleeding and so on. 3. Pulmonary edema: If children are nebulized for too long, it will lead to excessive inhalation of medication, which will easily lead to an increase in alveolar pressure, thus causing pulmonary edema. Children must be guided by a doctor or operated by a doctor for nebulization, if there is an adverse reaction after nebulization, it must be timely consultation.