Most likely due to a viral illness (most common) followed by bacterial super-infection (bacteria super-infection means when a bacterial infection occurs in setting where viral illness is also present). Less common is bacterial infection alone. A viral component is most likely present if symptoms do improve partially with antibiotics followed by immediate recurrence of symptoms after antibiotics completed resulting in repeated courses of antibiotics. In this scenario, it is best to avoid antibiotics unless the child is quite ill as only time will allow for the viral illness to resolve which is the main problem. Conservative care with saline spray to the nose followed by bulb suctioning is recommended. Daily Xlear Nasal Spray may also be helpful.
Steroids are naturally-occurring hormones that are produced by the adrenal glands. The corticosteroids have potent anti-inflammatory effects and are very effective in treating allergic inflammation in the nose. They are a "controller" type medication and work best when used on a regular "preventative" basis. They are usually only available by prescription. With seasonal allergies, daily use of these sprays should begin 1 to 2 weeks before the allergy season and continue throughout the season. In people with relatively constant or perennial allergic rhinitis, particularly if symptoms have been unresponsive to OTC or other treatments, daily use of intranasal steroids has been found very effective in controlling symptoms, particularly nasal congestion. The addition of antihistamines to this nasal spray will likely give even better results.