What Is the Main Idea?
Allergic rhinitis affects a large portion of the population (up to 30% of adults and 40% of children). The symptoms can range from mild to severe congestion, a runny nose, sneezing, and itchiness, and it can be associated with other conditions, such as allergic conjunctivitis and asthma. This post looks at some of the causes of allergic rhinitis, some ways to manage it, and the diagnostic process.
What Else Can You Learn?
Referencing the paper “Local Allergic Rhinitis: Lights and Shadows of a Mysterious Entity”, published in the journal International Archives of Allergy and Immunology, this post delves into the important but unusual case when someone has a nasal reaction to an allergen but tests negative in the skin-prick and blood tests. Why should we care about this form of the condition?
Why Is My House so Clean?
Whenever I start sneezing, my nose gets runny, and my eyes get itchy, I know why (or at least I think I do): It’s because of dust mites and it’s time to clean (or go outside and ignore the dust). These tiny relatives of ticks and spiders can occur in every location where you find mammals. The Latin names for the most common types are Dermatophagoides farinae and Dermatophagoides pteronyssinus. They live off the skin cells and dander (flakes of hair or fur) shed by mammals, including humans. It may be unpleasant to think of, but dust contains a lot of skin cells and dander — especially in my house, where we have two dogs, two cats, a rabbit, and, if we leave the back door open and unattended, three goats!
The reason for my sneezing is an allergy to the feces and bits of exoskeletons from the dust mites. It’s an uncomfortable and unpleasant reaction and it encourages me to get out the dusters and vacuum cleaner regularly. My diagnoses are allergic rhinitis (an inflammation of the lining of the nose caused by the microscopic particles entering my nose) and allergic conjunctivitis (an inflammation of the clear membrane that protects the eye).
I manage the allergy by minimizing the dust in the house; wearing a mask when I clean dusty areas; keeping the animals we live with groomed; and changing out of dusty clothes outside of our bedroom and sitting room, where I’d be most vulnerable to settled dust. We also have only one carpet in the whole house, and we wash blankets and quilts from sofas regularly. There are plenty of other measures that you can try, including antihistamine pills, anti-inflammatories, and inhalers.
Of course, not everyone has this allergy — some people can be in a dusty house with no reaction at all. And some people have a very different allergic reaction, with exposure resulting in eczema, congestion, or asthmatic attacks, the latter potentially very severe. In this post, I’m focusing on allergic rhinitis as there is an interesting variation of it with an unknown cause.
What Else Causes Allergic Rhinitis?
As we all know, dust mite feces and exoskeletons are not the only allergens that cause allergic rhinitis. Among many other particles, the wind-borne pollen of grasses and trees; cat, dog, rabbit, or horse dander; and mold spores can provoke mild to severe reactions.
Managing a pollen-related allergic rhinitis can involve limiting the time you spend outdoors when pollen levels are high; taking prophylactic antihistamines or using inhalers at those times of year; and changing out of outdoor clothes and washing your face, hands, and even hair immediately after you come in. Managing animal-related allergic rhinitis depends on the severity: It can be anything from avoiding direct contact with the relevant animals to not entering spaces with those animals at all. Mold-related allergic rhinitis is challenging because so many molds are invisible but minimizing mold in the living space and avoiding exposure outdoors, especially in late summer and fall, are important responses.
In all cases, your physicians and other healthcare workers should provide some insight into the management of your form of allergic rhinitis.
Is Allergic Rhinitis Common?
It should be noted that allergic rhinitis is very common, affecting 10–30% of adults and up to 40% of children, as stated in the paper “Local Allergic Rhinitis: Lights and Shadows of a Mysterious Entity” and references therein. Reactions can be mild at first but can worsen over time, and there are potential long-term consequences if the condition is not managed. That’s what makes it a good idea to get tested if you have the symptoms of allergic rhinitis. A specialist should perform certain tests to determine the “guilty” allergens. Commercially available home tests are not recommended as they can produce ambiguous results.
Testing for Allergies
The best-known specialist test is a skin-prick test, where they place droplets of multiple allergens in suspension on the inside of your forearm, then gently prick the skin. A welt (an itchy spot) will appear if you’re allergic to that particle. When I did the skin-prick test, the welts for D. arina and D. pteronyssinus feces and exoskeleton bits were large and sore. I had very small, slightly itchy welts for mold spores and one type of tree pollen, but no other reactions. Therefore, the focus of my allergy management has always been dust mites.
It is also possible to do blood tests. The specialist draws blood and tests to see its reaction to allergens. A positive diagnosis is when your blood produces the immunoglobulin E (IgE) antibody in response to an allergen.
Some additional tests may be done to check for: damage to the lining of the nose and throat due to exposure to the allergen; polyps and other growths occurring in response to continuous inflammation or damage; and the level of restriction of the airflow due to the inflammation, damage, or growths.
Of course, rhinitis might not be caused by allergies at all. There’s also infectious rhinitis, caused by viruses and bacteria, and non-allergic rhinitis, which might be caused by exposure to fumes, certain foods, and non-allergenic particles. You’ve certainly had infectious rhinitis at some point, since it’s commonly associated with rhinoviruses (many of which are responsible for “the common cold”), and if you’ve sneezed going through a department store’s perfume department, you’ve had non-allergic rhinitis.
Why Is Local Allergic Rhinitis Interesting?
Local allergic rhinitis is a possible diagnosis when someone has the symptoms of allergic rhinitis in response to environmental exposure to an allergen but negative skin-prick and IgE tests. For example, if someone had consistently sneezed and developed a runny nose in a dusty environment but tested negative for an allergy to D. arina and D. pteronyssinus feces and exoskeleton bits, the diagnosis would be local allergic rhinitis. Some other conditions might need to be ruled out along the way, but this is a possible diagnosis.
That’s what the paper “Local Allergic Rhinitis: Lights and Shadows of a Mysterious Entity” focuses on. As the authors explain, the word “local” in the name refers to the idea that the body might only product IgE locally (e.g., only in the nasal area) rather than systemically (i.e., in the whole body). That would explain why the traditional tests don’t return positive results — they test the response of skin or blood that is distant from that area.
Testing negative for allergic rhinitis in the two traditional tests can result in a patient not getting the medical treatment and advice they need. Not every state healthcare system recognizes local allergic rhinitis, despite the evidence to back its existence. This means a patient may be given the wrong advice or treatment — or no treatment or advice at all. Local allergic rhinitis should be managed similarly to allergic rhinitis: Depending on the severity of the reaction, avoid the allergen, avoid bringing the allergen into the bedroom and other sensitive areas of the house, wear a mask, take antihistamine medication, etc. However, patients may need to push for additional diagnostics, and sharing “Local Allergic Rhinitis: Lights and Shadows of a Mysterious Entity” with your healthcare provider might help.
Note: One of the authors of the paper declared that they have relationships with companies that produce or sell antihistamine treatments relevant for described medical conditions. It is normal for authors to declare this in case it might be perceived as a conflict of interest. More detail can be found in the Conflict of Interest statement by visiting the original article page.