How Common Is Non-Allergic Rhinitis Or Is It A Rare Disease?

The nasal mucosa is inflamed in rhinitis. The inflammatory changes in the nasal mucosa are often caused by allergic rhinitis such as hay fever, which, however, must be differentiated from non-allergic rhinitis. This nonallergic form is usually nasal inflammation caused by infections (cough and colds), medically induced changes, nasal polyps, foreign bodies, etc.

The nasal mucosa normally produces the mucus necessary for moistening and purifying the inhaled air. If the mucous membrane is irritated, more mucus is produced. When the swelling causes the air passage through the nose narrower, the nose becomes blocked and excessive mucus or nasal secretions are produced. ⁽¹⁾

A regression of the nasal mucous membrane (atrophy, e.g., as a result of some medicines) can lead to such complaints as the cleansing function of the nasal mucosa then is disturbed due to the dry nose.

Nonallergic rhinitis is becoming more common in recent times with increased air pollution (with more particulate matter present in the breathing air) causing nasal irritation. The unclean air also accommodates pathogenic bacteria and viruses causing nonallergic rhinitis. The tendency of people having over-the-counter medicines and other chemicals or herbal supplements without consulting the doctor or pharmacists may also increase the risk of nonallergic rhinitis.

Whatever the cause, seek medical help if it is not going away after one week and using over-the-counter medicines and relievers.

There are several forms of non-allergic rhinitis:

Chronic Rhinitis: Chronic rhinitis is usually an extension (resolved within 30 to 90 days) of subacute inflammatory or infectious viral rhinitis. Blastomycosis, leishmaniasis, leprosy, rhino sclerosis, rhinosporidiosis, syphilis, and tuberculosis, all characterized by the formation of granuloma and the destruction of soft tissues, cartilages, and bones, are rarely linked.

This results in obstruction of the nasal cavity, purulent rhinorrhea, and regular nasal bleeding. The development of indurated inflammatory tissue in the lamina propria often causes progressive nasal obstruction. Hemorrhagic polyps are common in rhinosporidiosis. Low airborne irritants and hygrometry may lead to chronic rhinitis. ^{(2) (3)}

Acute Rhinitis: Vasodilation and edema are common in acute rhinitis and often result from usual cough and cold. However, staphylococcal, pneumococcal, and streptococcal infections may also result in acute rhinitis. ⁽⁴⁾

Vasomotor Rhinitis: Vasomotor rhinitis, sometimes named non-allergenic rhinitis, is a recurrent disease that causes nasal mucosal intermittent vascular engorgement resulting in sneezing and rhinorrhea. The exact etiology is not clear and there is no recognized allergen responsible for the condition. This is particularly aggravated by a dusty environment. ⁽⁵⁾

Atrophic Rhinitis: Atrophic rhinitis, a form of chronic rhinitis, induces atrophy and sclerosis of the mucosa; the ciliated pseudo-stratified columnar epithelium of the mucosa is transformed into the squamous epithelium and the thickness and vascularity of the lamina propria decreases. Atrophy of the nasal mucosa is often observed in the elderly. ⁽¹⁾

There can be various causes for the condition which are not always easy to detect. It is usually unclear why some people are affected. In some patients, constant infections (bacterial, viral or fungal) can contribute to the disease. Even high levels of dust and irritants in the air can lead to protracted inflammation of the nasal mucosa. Smoking plays an important role along with nasal drops and other drug uses (some blood pressure medicines). Pronounced temperature fluctuations of the inhaled air can be an important trigger.

Excessive use of common nasal drops may favor the development of rhinitis because the decongestant agents may cause a permanent change in the mucous membrane (atrophy).

Narrowing of the nasal tract can also cause this problem (development of polyps, mucosal proliferation, an oblique nasal septum, tumors or foreign bodies in the nose). Even a disturbed blood circulation of the nasal mucosa (in case of malfunction of the blood vessels) may be the cause of the symptoms. Other diseases like tuberculosis, heartburn or acid reflux may suffer from nonallergic rhinitis.

Sometimes no specific cause of the disease can be found in some patients even after thorough diagnosis (idiopathic rhinitis). ⁽¹⁾

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