There is no fastest cure for rhinitis in a 5 year old child. According to its causes, it can be categorized into infectious rhinitis and allergic rhinitis, which need to be treated with general therapy, medication, surgery, and so on. 1. Infectious rhinitis: acute rhinitis can be taken to use saline nasal rinse, improve the symptoms, accompanied by severe nasal congestion, can use decongestant, such as 0.5% ephedrine nasal drops, ephedrine hydrochloride nasal drops, etc. If the combination of bacterial infection, can be applied systemically. If combined with bacterial infection, systemic application of antibiotic drugs, such as amoxicillin clavulanate potassium, cefadroxil granules, etc., but pay attention to whether the drug allergy. 2. Allergic rhinitis: local use of glucocorticoid drugs, such as mometasone furoate nasal spray, budesonide nasal spray, can help reduce the inflammatory response of the nasal cavity. In addition, the systemic use of antihistamines, such as cetirizine hydrochloride drops, loratadine granules and other anti-allergy treatment. All of the above medications need to be prescribed by the doctor, and parents should not use the medications on their own.