Rhinoconjunctivitis

Rhinitis is characterized by one or several of the following symptoms: nasal congestion, runny nose, post-nasal drip, sneezing, red eyes (conjunctivitis), and itching of the nose or eyes. It may be allergic in origin, but isn’t always. It may be present only during a specific season, or present year-round with or without periods of worsening.

Mechanisms of allergic rhinitis

Allergic rhinitis is defined by the presence of antibodies (IgE) which recognize certain allergens. When these antibodies are exposed to the allergen, they bind the allergen and this leads to an inflammatory reaction. This reaction is characterized by the liberation of several inflammatory mediators (histamine, tryptase, leukotrienes…) which in turn leads to the signs and symptoms typical of allergic rhinitis.

Classification of rhinitis

Not all forms of rhinitis are associated with an inflammatory component.

There are several possible reasons for rhinitis:

1. Allergic (seasonal, perennial, episodic)
2. Non-allergic:

1. Vasomotor (cold, exercise, irritants): certain factors trigger the rhinitis via a reflex.
2. Gustative (example: ingestion of spicy food can trigger a reflex leading to a runny nose)
3. Infectious (infection of the upper respiratory tract by a virus or bacteria)

3. Occupational: in which the symptoms are only triggered by an element in the workplace
4. Other factors that can contribute to a rhinitis:

1. Hormonal, hypothyroidism
2. Medication: rhinitis medicamentosa (oral or topical decongestants), contraceptives, antihypertensives, cardiac medicine, aspirin and anti-inflammatories. The benefits of several of these medicines may be more important than the side effects, although is invariably recommended to avoid prolonged utilisation of oral and topical decongestants.
3. Atrophic mucosa
4. Other inflammatory/immunologic disorders: granulomatous infection, granulomatous inflammation: Wegners granulomatosis, sarcoidosis, Churg-Strauss…It is important to note that these health conditions usually present with other signs and symptoms, and not simply a rhinitis.

Clinical approach to allergic rhinitis

For allergic rhinitis, it is first important to identify the triggering elements in order to enact measures to avoid exposure to these allergens. The same is true of other irritating substances

The most common inciting allergens are: pollens, molds, dust mites, animal dander, and certain insects (cockroaches) .

Prevention and treatment

It is important to enact environmental control measures to avoid the allergens that are causing the problem (see the section on Respiratory allergens). Environmental control measures may be insufficient in many cases, and often one needs to consider pharmacological therapy:

• When the symptoms are light and occasional, antihistamines may suffice:
• Non-sedating antihistamines: loratadine (Claritin™), cetirizine (Reactine™), desloratadine (Aerius™), fexofenadine (Allegra™) as needed.
• If the symptoms are present more than 50% of the time:
• Nasal sprays prescribed by a doctor (intra-nasal corticosteroids: Avamys™, Flonase™, Nasacort™, Nasonex™,Omnaris™, Rhinocort™).
• It is recommended to take these medications on a regular basis for the maximum effect.
• In addition, one can also take regular antihistamines.
• Eye drops prescribed by a physician.
• Other: leukotriene receptor antagonists (Montélukast-Singulair™)
• Immunotherapy or allergy shots (see the section on Immunotherapy)
• If these measures aren't sufficient to control your symptoms, it is important to follow-up with your allergist.

__________________________

Simon Hotte, MD FRCPC
(translation: Andrew Moore, MD FRCPC)