Generally, the earlier the treatment, the better. Some chronic problems associated with allergies can cause permanent damage if left untreated for a long period of time. Evidence shows that if the inflammation of the airway (asthma) is not controlled, chronic irreversible scarring of the airway can occur; when this occurs, it will be more difficult to revert the process. This type of irreversible lung injury can also occur during early childhood. Being aware of the nature of allergic disease is the first step in controlling it. Allergen avoidance, medications and/or immunotherapy (allergen vaccination) may be necessary for allergic rhinitis and asthma. For severe food allergy, accurate identification of the allergen(s) is important.