How long it takes to cure an allergy is related to the duration of the disease, the type of allergen, the amount of exposure, the individual’s constitution, and the treatment, and cannot be generalized. Most acute allergies, even severe ones that require resuscitation such as anaphylaxis, can return to normal within 24 hours. Chronic allergic inflammation, on the other hand, is prone to recurring attacks and is difficult to cure. The three main types of common allergic diseases are food allergy, inhalation allergy and contact allergy. Food allergy can present a variety of symptoms, including itchy skin, nausea, vomiting, diarrhea, dizziness, etc., and any food can be an allergen; inhalation allergy is most common in diseases such as allergic rhinitis and allergic asthma; contact allergy is most common in contact allergic dermatitis. Most allergy patients can generally get better within one month after scientific and regular treatment, and those with mild attacks can get better in as little as 2-3 hours after standardized anti-allergy treatment. Regardless of the type of allergic reaction, the prerequisite for improvement is no further exposure to the allergen. If prolonged exposure to allergens is unavoidable, the allergy may persist and eventually develop into a chronic allergic disease, which may require months of medication.