Allergy is not always behind rhinitis symptoms: separating allergic from nonallergic.
"Allergic and nonallergic rhinitis can be difficult to separate because there is a huge overlap and many patients have both. It's important to understand that diagnosing one doesn't necessarily exclude the other," said Dr. Pollart of the University of Virginia, Charlottesville.
Allergic rhinitis affects as many as 30% of adults and 40% of children. In children it's common to see allergic rhinitis in the preschool years, then an abatement, and then a return in the patient's 30s and 40s.
Treating allergic rhinitis can also improve other comorbid conditions, such as asthma and sinusitis. "Patients with asthma who have coexisting allergic rhinitis will not have complete response to their asthma [treatment] if their rhinitis is left untreated," she said.
Allergic rhinitis is primarily caused by exposure to a seasonal or perennial inhalant. Allergic rhinitis has four cardinal symptoms: congestion, rhinorrhea, sneezing, and itching.
"These four are really the hallmarks of allergic disease. If you only have two symptoms, you're much more likely to have nonallergic rhinitis," Dr. Pollart said. Patients with chronic allergic rhinitis due to a perennial allergen may have less sneezing and itching.
Roughly 50% of rhinitis cases don't have an allergic etiology, however. Nonallergic rhinitis symptoms can be episodic or perennial, and this type of rhinitis is not IgE-mediated.
Nonallergic rhinitis can stem from infection, medications, hormones, and can be vasomotor in nature. Bacterial rhinosinusitis is an acute condition in which patients have symptoms for 7 days or longer. Bacterial sinusitis is likely if the patient has three of the following four symptoms: predominantly unilateral purulent rhinorrhea, localized pain, bilateral purulent rhinorrhea, and the presence of pus on physical examination of the nasal cavity. Treat the patient with an antibiotic for 10-14 days.
In vasomotor disease, patients present with nasal obstruction and rhinorrhea but usually without sneezing or itching. Vasomotor disease is not eosinophilic or neutrophilic and is often triggered by environmental factors such as strong odors and temperature changes. "It's very difficult to treat and it's pretty much a diagnosis of inclusion," said Dr. Pollart.
There is a special and rare case of nonallergic rhinitis that involves eosinophilic response.
In nonallergic rhinitis with eosinophilia syndrome, patients have congestion, rhinorrhea, and itching, and often lose their sense of smell. Skin testing and radioallergosorbent testing will show no IgE response.
However, on examination of a nasal smear, eosinophils are present. "The nice thing about this disease is that even if you don't separate it well from allergic disease, it responds to intranasal corticosteroids--one of the first-line therapies for allergic rhinitis."
Hormonal rhinitis--congestion and rhinorrhea--is often seen in pregnant women, usually in the mid-first trimester, and it can last until delivery. "This is so tough to treat. For pregnant women it seems to go on and on and nothing really makes a difference. Plus they have concerns about the medications," said Dr. Pollart.
Other hormonal changes, such as occurs with puberty and the initiation of oral contraceptives, can also trigger this type of nonallergic rhinitis. "If a patient develops rhinitis after beginning oral contraceptives, it's important to think of this as a potential cause." Hypothyroidism can also cause rhinitis.
Drug-induced rhinitis is often related to drugs used for hypertension. If there are no complications, such as sinusitis, this type of rhinitis can be treated symptomatically. Rhinitis medicamentosa is a special case, caused by the overuse of topical decongestants.
This rebound phenomenon occurs after 5-7 days of regular use. Patients can be resistant to treatment because they become dependent on the topical agent for congestion relief.
In terms of treatment, the evidence for avoidance as a means of primary or secondary prevention is weak.
"It can be a great adjunct and is certainly something that I recommend, but it has not been as helpful as we had hoped it would be in terms of eliminating or preventing disease," Dr. Pollart said at the meeting.
Rhinitis medications fall into two classes: antihistamine and anti-inflammatory. Anti-inflammatory nasal corticosteroids appear to be the most effective, although no one type is better than another. The newer nonsedating antihistamines are often the patient's drugs of choice. At the onset of symptoms, both antihistamines and nasal corticosteroids may be necessary at the highest dosages.
"I will also use a short course of oral corticosteroids at onset for very severe cases," said Dr. Pollart.
There has been concern about growth suppression in children with the use of intranasal corticosteroids. In one trial, intranasal beclomethasone was associated with a statistically significant difference in growth.
However, no difference in growth has been noted with the use of mometasone (Nasonex), which is indicated in children as young as age 3 years.
If congestion is a particular problem, use a newer antihistamine (loratadine, fexofenadine [Allegra], or cetirizine [Zyrtec]) that has a decongestant added. Alternatively, use a first-generation antihistamine (diphenhydramine or chlorpheniramine) that has a decongestant effect. Loratadine and cetirizine are approved for children age 3 years and older.
Azelastine (Astelin) is the only intranasal antihistamine currently approved in the United States. It's as effective as oral antihistamines and is indicated for nonallergic rhinitis as well. Ipratropium bromide 3% solution (Atrovent) is another choice for treating nonallergic rhinitis.
Cromolyn sodium (Nasalcrom) is an anti-inflammatory that provides a protective effect after about 4 days. It has a strong safety profile, making it an attractive option for children and pregnant women, Dr. Pallart said.
Leukotriene modifiers are a new option in the last year. Montelukast (Singulair), which is indicated for seasonal allergic rhinitis, is at least as effective as loratadine. It's also effective for mild to moderate asthma.
Use of a leukotriene modifier may allow a reduction in other medications. It's also indicated for children as young as age 2 years.
RELATED ARTICLE: Blame it on the cat.
Have a cat allergy and think you're in the clear because you don't have a cat? Think again.
"Cat allergen is everywhere," said Dr. Pollart. She related the story of a colleague who developed asthma related to a cat allergy even though her only exposure was from the jacket of a coworker that was hung on the back of her office door. "The coworker had three cats. She came to work every day in the winter and hung her coat on the door. My colleague became progressively sicker and sicker and eventually ended up on prednisone."
This was a carpeted room into which more cat allergen was brought every day. Cat allergen becomes airborne very easily, so it's circulating all the time. Even when a cat is removed from a home, it can take up to 6 months before all of the cat allergen is gone, said Dr. Pollart.
"This was a situation where no known cat exposure led to significant cat allergies and asthma." So always think of the potential for exposure to cat allergens regardless of whether an allergy patient lives with a cat.
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|Title Annotation:||Clinical Rounds|
|Publication:||Family Practice News|
|Date:||Dec 1, 2003|
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