Not all symptoms in the nasal passage are caused by allergy or infection. Similar symptoms can be caused by mechanical blockage, use of certain medications, irritants, temperature changes or other physical factors. Rhinitis can also be a feature of other diseases and medical conditions.
Drug-induced nasal congestion can be caused by birth control pills and other female hormone preparations, certain blood pressure medications and prolonged use of decongestant nasal sprays.
Decongestant nasal sprays work quickly and effectively, but they alter how the nasal passages normally work. After a few weeks of use, nasal tissues swell after the medication wears off. The only thing that seems to relieve the obstruction is more of the medicine, and the medication's effect lasts for shorter lengths of time. Permanent damage to the nasal tissues may result. Consultation with a physician to "get off" the medication is often necessary.
Cocaine also alters how the nasal passages normally work, causing a condition identical to, or even more severe than that produced by decongestant nasal sprays. If you use cocaine, it is important to tell your physician so that appropriate therapy can be prescribed.
Irritant rhinitis, or "vasomotor rhinitis" describes a group of poorly understood causes of rhinitis, with symptoms not caused by infection or allergy. Many people have recurrent or chronic nasal congestion, excess mucus production, itching, and other nasal symptoms similar to those of allergic rhinitis, but the disorder is not caused by allergy.