Researchers aimed to better understand the intricacies of local allergic rhinitis and how it differs from allergic rhinitis.
After a systematic review of local allergic rhinitis, researchers came to the common conclusion that the disease is a novel entity in need of more research to further understand its diagnosis and achieve a consensus on its proper definition. They were able to separate the necessary diagnosis, treatment, and prevalence of the condition compared with allergic rhinitis, detailing key differences in the diseases.1
“Patients with non-allergic rhinitis were previously considered non-allergic because they had negative skin prick test responses and non-detectable serum-specific IgE [Immunoglobulin E]. However, some of these subjects react to an allergen with nasal symptoms, are positive for nasal allergen challenge, and have mucosal IgE. This suggests that they are suffering from what is now termed local allergic rhinitis,” wrote authors of the study, published in the European Review for Medical and Pharmacological Sciences.1
Because local allergic rhinitis patients were testing negative for skin prick responses and exhibiting non-detectable serum-specific IgE, researchers once classified the condition as “non-allergic.” But since positive nasal allergy testing showed this classification to be false, non-allergic rhinitis evolved into local allergic rhinitis.
To further understand local allergic rhinitis, researchers explored literature on the topic and compared it with already known definitions and understandings of allergic rhinitis.
Researchers aimed to better understand the intricacies of local allergic rhinitis. | image credit: Volha Zaitsava / stock.adobe.com
“Allergic rhinitis occurs when disruption of the epithelial barrier allows allergens to penetrate the mucosal epithelium of nasal passages, inducing a T-helper type 2 inflammatory response and production of allergen-specific IgE,” wrote Bernstein et al.2
Since allergic rhinitis and local allergic rhinitis are so often compared, it’s sometimes difficult to separate the 2 conditions when studying their proper diagnostic processes, treatment options, and overall prevalence in society.
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Symptoms of local allergic rhinitis include nasal itching, sneezing, rhinorrhea, and nasal congestion/obstruction, frequently coupled with ocular symptoms.1 Because these symptoms are so similar to those of allergic rhinitis, it can be difficult to diagnose local allergic rhinitis.
However, using previous literature regarding local allergic rhinitis, researchers were able to better understand the intricacies of the condition and came to a best process for diagnosis.
“[Local allergic rhinitis] involves type 2 nasal inflammation with local IgE and cannot be diagnosed by systemic methods, such as skin prick or blood IgE tests. A nasal allergen challenge is necessary for diagnosis,” wrote the authors.1
The nasal allergen provocation test is the gold standard in diagnosing local allergic rhinitis. Mimicking the allergic reaction from natural allergen exposure, this test uses objective measurements to evaluate nasal blockage.1
However, although it’s considered the best process in diagnosing local allergic rhinitis, the nasal allergen challenge must be improved for researchers to further understand the prevalence and scope of local allergic rhinitis.
“This procedure is time-consuming, may take many sessions for each patient, and is only used in a few places since it requires well-trained workers,” they continued.1
Because the nasal allergen provocation test is so time- and resource-consuming, researchers still fear the prevalence of local allergic rhinitis is much more widespread than they previously thought.
“Studies evaluating individuals with rhinitis have shown that [local allergic rhinitis] is an under-/mis-diagnosed disease that may affect between 10%-47% of patients previously classified as non-allergic rhinitis and may involve 25.7% of rhinitis patients referred to an allergy clinic,” the authors wrote.1
Although the lines are blurred between what types of allergic rhinitis are actually defined as local allergic rhinitis, researchers recently updated the most common clinical profile of a patient with local allergic rhinitis.
“As with [allergic rhinitis] patients, [local allergic rhinitis] patients can have both persistent and intermittent symptoms, as well as perpetual or seasonal ones, and their intensity can be characterized as mild, moderate, or severe. The most common clinical profile of [an] [local allergic rhinitis] patient is a non-smoker with moderate [to] severe chronic perennial rhinitis, typically coupled with conjunctivitis and asthma,” they wrote.1
Despite several common traits between both local allergic rhinitis and allergic rhinitis, researchers are gradually gathering literature that separates the 2 conditions. But with challenges in understanding the full scope of the local allergic rhinitis, researchers concluded that their review was aimed at furthering interest in the topic rather than coming to a final conclusion on the condition.
“The target outcomes and possible benefits of this review are to achieve a consensus for the study and diagnosis of [local allergic rhinitis] and increase interest in this area,” they concluded.1
READ MORE: Asthma and Allergy Awareness Month: Resources Roundup
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