Formaldehyde poisoning in infants is usually divided into acute poisoning and chronic poisoning. Acute poisoning can be manifested by the sudden appearance of a poor complexion, poor mental state, or even coma, and some infants may also have vomiting and other manifestations. There may be respiratory symptoms, such as an irritating dry cough, or even difficulty breathing. In the case of chronic formaldehyde poisoning, there is usually a suppression of the bone marrow hematopoietic system and anemia may occur, for example, the infant may look pale, and the development may be delayed and the intelligence may not be as good as that of a normal infant.