Refresher on rhinitis and the conditions that mimic it

Rhinitis is a common condition with a variety of underlying causes. But it is often associated with other upper airway conditions, and has several treatment options. Rhinitis affects up to 25% of Canadians, and consists of two main types, allergic rhinitis (AR) and non-allergic rhinitis (NAR)—with subtypes of NAR including autonomic, infectious, and idiopathic (unknown). According to a 2018 review on AR by Canadian researchers in Allergy Asthma Clinical Immunology (AACI), AR affects 10% to 20% of the Canadian population and is increasing, with higher numbers in children. While allergic rhinitis used to be considered as a localized disorder affecting just the nose and nasal passages, evidence now suggests it may represent a component of a systemic airway disease involving the entire respiratory tract. It is commonly associated with other respiratory issues such as asthma, COPD and sinusitis. Read: Association between asthma and autoimmune disorder myasthenia gravis: meta-analysis When it comes to AR, there are different types. One is local allergic rhinitis (LAR) which is a localized allergic response in the nasal mucosa, but no systemic atopy. Treatment approaches are not well understood, but some evidence suggests allergen immunotherapy may be helpful, said Dr. Harold Kim, chief of the division of clinical immunology and allergy at Western University. He spoke to the Medical Post in an interview. Chronic NAR, on the other hand, affects 17% to 52% of adults, and up to 34% of rhinitis patients may have a mix of both AR and NAR or “mixed rhinitis” (MR), according to the U.S. “Rhinitis 2020: A practice parameter update” in the Journal of Clinical Immunology (JCI). Treatment approaches can vary depending on the underlying cause, frequency of symptoms and severity. There is also occupational rhinitis which can have either intermittent or persistent symptoms that can be attributed to workplace exposure and be non-allergic or allergic in nature. Treatment usually entails avoidance of triggers and pharmacotherapy such as with second-generation antihistamines. Some studies suggest as many as 25% of people diagnosed with AR may actually have MR, and they tend to have more frequent and severe symptoms, and may be more likely to have asthma than people with AR. A 2020 overview of new treatments in the Journal of Allergy and Clinical Immunology Practice (JACIP) for both rhinitis and sinusitis stated that more than 90% of patients with seasonal AR reported symptoms being triggered by non-allergic sources suggesting that MR is more common than thought and likely underdiagnosed. In addition, patients with MR generally have the same symptoms as people with AR, often develop symptoms later in life, have no family history of atopy, lack seasonality for symptoms, don’t have problems with furry pets, but do have symptoms triggered around irritants such as fragrances. The most common form of MR is vasomotor rhinitis which involves neurogenic pathways. Mimickers Even more confusing, several conditions can mimic rhinitis (often with sinus symptoms as well). These include nasal sepal deviation, nasal valve collapse, turbinate hypertrophy in the sinuses, pharyngonasal reflux, cerebral spinal fluid leak, adenoidal hypertrophy, nasal or sinus tumour, nasal foreign body (especially in children). Adenoidal hypertrophy, vasculitis and other systemic diseases. For rhinitis patients in general, a good history needs to be taken to determine triggers, and sort out whether it is an allergic or non-allergic problem. Any medications a patient is using should be considered as many can cause rhinitis symptoms, such as beta-blockers, acetylsalicylic acid, non-steroidal anti-inflammatories, ACE-inhibitors, hormone therapy, nasal-sprays, and others, Dr. Kim said. This history should include asking about family history of atopy, asthma, sinus involvement, nasal polyps and other details, he said. Nasal, ocular symptoms such as rhinorrhea, nasal itching, sneezing, allergic conjunctivitis and nasal congestion should all be evaluated. Diagnostic tests such as skin-prick tests can also be ordered to help confirm AR. Initial treatments for mild AR include allergen avoidance, nasal saline rinses, and second-generation oral antihistamines such as loratadine, desloratadine, fexofenadine or rupatadine. Newer antihistamines on the Canadian market include rupatadine and bilastine. Decongestants can offer some limited help but should not be used long-term as over-use can cause rhinitis symptoms, said Dr. Kim. The next step up for treatment may include either intranasal corticosteroids, or combination intranasal corticosteroid/antihistamine sprays. Failing those, the leukotriene receptor antagonists (LTRAs) montelukast (zafirlukast is not indicated for this in Canada) can be tried but generally are not as effective as the intranasal corticosteroids, he said. Referral to a specialist can help with more persistent cases. Evidence suggests allergen immunotherapy (allergy shots) are effective for AR after about three years. Another approach is sublingual immunotherapy (SLIT) which uses a tablet of allergen extract placed under the tongue until it dissolves. Both allergy shots and SLIT are indicated for those for whom other therapies weren’t sufficient. Some studies show SLIT has fewer adverse reactions than allergy shots, but both are disease-modifying, with effects can persist for years after treatment. New treatments are being studied, and include intralymphatic immunotherapies (ILIT) which proposes ultrasound-guided injection of allergens directly into the lymph nodes, with preliminary studies showing safety and efficacy. For people with sinusitis and nasal polyps in the mix, chronic rhinosinitus, the biologic agent dupilumab (also used for severe asthma) was approved or this indication in the U.S. It has been found to reduce both sinus and nasal symptoms. Other biologics are also being studied for chronic rhinosinitus. Details for assessing and managing allergic rhinitis can be found in the ARIA guidelines.

Refresher on rhinitis and the conditions that mimic it

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