b) Non allergic -Rhinitis

NONALLERGIC RHINITIS — Nonallergic rhinitis is a common condition characterized by the chronic presence of one or more of the following: nasal congestion (stuffiness), rhinorrhea, and postnasal drainage. It is a diagnosis of exclusion and thus specific etiologies must be excluded (such as immunologic [especially due to immunoglobulin E (IgE) sensitivities], infectious, pharmacologic, structural, hormonal, vasculitic, metabolic, and atrophic causes).

Clinically, it is distinguished from allergic rhinitis by the following:

●Onset at a later age

●Absence of nasal and ocular itching and prominent sneezing

●Nasal congestion and postnasal drainage are prominent symptoms

●Symptoms are perennial

Typical triggers in nonallergic rhinitis include irritant odors and strong fragrances, such as tobacco smoke, perfumes, diesel and car exhaust (ie, patients become congested when sitting in traffic), cleaning products, newsprint, changes in temperature, and alcoholic beverages [5]. Subtypes of nonallergic rhinitis include:

●Vasomotor rhinitis, which is characterized by intermittent symptoms of congestion (stuffiness) and/or watery nasal discharge, and an exaggerated reaction to nonspecific irritants, such as air pollution or temperature changes, especially exposure to cold, dry air [6].

●Gustatory rhinitis, which is an episodic condition with prominent watery rhinorrhea triggered most often by hot or spicy foods, and is caused by a vagally-mediated reflex [7].

Diagnosis and management of the different forms of nonallergic rhinitis are reviewed elsewhere. (See "Chronic nonallergic rhinitis".)

Systemic medications — Certain systemic medications have been implicated in causing rhinitis symptoms through local inflammation, neurogenic effects, or unknown mechanisms. The presenting symptom is usually nasal congestion without other nasal symptoms. These drugs include the following (table 1) [11]:

●Alpha-blockers, such as clonidine, methyldopa, guanfacine, prazosin, doxazosin, and phentolamine

●Other antihypertensives, such as angiotensin converting enzyme (ACE) inhibitors, beta blockers (both oral and ophthalmic preparations), calcium channel blockers,reserpine, mecamylamine, amiloride, hydralazine, chlorothiazide, and hydrochlorothiazide

●Erectile dysfunction drugs, such as sildenafil, tadalafil, and vardenafil

●Some antidepressants, benzodiazepines, psychotropics, and antiepileptics, such as chlordiazepoxide-amitriptyline, chlorpromazine, risperidone, thioridazine, andgabapentin

●Intermittent use of nonsteroidal antiinflammatory drugs (NSAIDs) (in patients with aspirin-exacerbated respiratory disease) (see "Aspirin-exacerbated respiratory disease")

●Estrogens and progesterone may contribute to rhinitis symptoms, although data from clinical trials have been mixed [12-17]