Demographics and epidemiology of allergic and nonallergic rhinitis.

Chronic rhinitis symptoms are among the most common problems presenting to physicians. When approaching this problem the diagnostic challenge is to determine the etiology, whether it is allergic, nonallergic, or perhaps an overlap of both conditions. Estimates of the prevalence of allergic rhinitis range from as low as 9% to as high as 42%. Although nonallergic rhinitis is a well-recognized diagnosis, its prevalence has not been studied definitively. If the assumption is made that approximately 20% of the U.S. population has allergic rhinitis, then 58 million people in the United States suffer from this diagnosis. Population survey results have estimated that 19 million Americans suffer from nonallergic rhinitis. Frequently, nonallergic rhinitis occurs in tandem with allergic disease and presents as mixed rhinitis. Because 44% of patients with allergic rhinitis may have concomitant nonallergic rhinitis, it is estimated that an additional 26 million people have a nonallergic component to their rhinitis (mixed rhinitis). Therefore, a total estimated 45 million people have either pure nonallergic rhinitis or mixed rhinitis. Because nonallergic rhinitis is common, it is important to differentiate this condition from rhinitis of allergic etiology. Once the diagnosis is established, an appropriate treatment plan tailored to a specific diagnosis can be optimally designed.

Update on nonallergic rhinitis.

BACKGROUND: Although nonallergic rhinitis is a well recognized entity, its incidence and therapy have not been definitively studied. Recent epidemiologic studies and treatment trials have furthered our knowledge regarding the frequency of occurrence of this disorder and effective treatment modalities. OBJECTIVE: To review and put into perspective recent advances in our knowledge regarding the incidence and significance as well as therapy of chronic nonallergic rhinitis. In addition, based upon these data, to propose a classification of this disorder. DATA SOURCES: The MEDLINE database and the results of a national survey of allergists (National Rhinitis Task Force) conducted in 15 allergy practices involving 975 patients. CONCLUSIONS: Nonallergic rhinitis is a common disease that probably affects as many as 17 million Americans. Of equal importance is that, based on available data, approximately 22 million people suffer with a combination of nonallergic rhinitis and allergic diseases (mixed rhinitis). Both nonallergic and mixed rhinitis occur more frequently in adults than in children, may be more common in female patients than in male patients, and are more likely to be perennial than seasonal. Agents demonstrating efficacy (based on controlled trials or having approval by the FDA) for the therapy of nonallergic rhinitis are azelastine and topical nasal steroids.

Complications of allergic rhinitis.

With unfortunate high frequency, clinicians consider allergic rhinitis to be more of a nuisance than an illness. When in fact, allergic rhinitis is not only a very common disease process, affecting up to a cumulative frequency of 42% of the U.S. population by age 40, but can lead to significant short-term and long-term medical complications. Poorly controlled symptoms of allergic rhinitis may contribute to sleep loss, secondary daytime fatigue, learning impairment, decreased overall cognitive functioning, decreased long-term productivity and decreased quality of life. Additionally, poorly controlled allergic rhinitis may also contribute to the development of other related disease processes including acute and chronic sinusitis, recurrence of nasal polyps, otitis media/otitis media with effusion, hearing impairment, abnormal craniofacial development, sleep apnea and related complications, aggravation of underlying asthma, and increased propensity to develop asthma. Treatment of allergic rhinitis with sedating antihistamine therapy may result in negative neuropsychiatric effects that contribute to some of these complications. Sedating antihistamines may also be dangerous to use in certain other settings such as driving or operating potentially dangerous machinery. In contrast nonsedating antihistamines have been demonstrated to result in improved performance in allergic rhinitis.

Prevalence of cross-sensitivity with acetaminophen in aspirin-sensitive asthmatic subjects.

OBJECTIVE: Cross-sensitivity between aspirin and acetaminophen in aspirin-sensitive asthmatic patients has been reported with frequencies ranging from 0% to 29%. The relationship is dose-dependent for acetaminophen challenges, ranging between 300 and 100 mg. METHODS: To determine the prevalence of cross-sensitivity to high-dose acetaminophen, we performed single-blind acetaminophen oral challenges with 1000 mg and 1500 mg in 50 aspirin-sensitive asthmatic patients and in 20 non-aspirin-sensitive asthmatic control subjects. RESULTS: Overall, 17 of 50 (34%) of aspirin-sensitive asthmatic patients reacted to acetaminophen in doses of 1000 to 1500 mg (95% confidence interval: 20% to 49%). By contrast, none of the 20 non-aspirin-sensitive asthmatic patients reacted to acetaminophen (95% confidence interval: 0% to 14%). This difference was highly significant (p = 0.0013), supporting the hypothesis that cross-sensitivity between aspirin and acetaminophen is unique in aspirin-sensitive asthmatic patients. CONCLUSION: Although high-dose ( > 1000 mg) acetaminophen cross-reactions with aspirin were significant with respect to frequency (34%), such reactions included easily reversed bronchospasm in only 22%, and were generally mild. We recommended that high doses of acetaminophen (1000 mg or greater) should be avoided in aspirin-sensitive asthmatic patients.

Inflammatory mediator release on conjunctival provocation of allergic subjects with allergen.

To evaluate the role of inflammatory mediators in the pathogenesis of the ocular allergic response, 23 subjects with positive histories of allergies to either cat dander or ragweed pollen and positive skin tests to the appropriate allergen extract were recruited and were subjected to conjunctival provocation. The tear duct of the left eye of each subject was blocked with a collagen plug while the right eye was left unplugged. In all cases, the eye was initially provoked with saline and subsequently with the appropriate allergen extract. Nonallergic subjects, or allergic subjects provoked with nonrelevant allergen, were used as control subjects. After each provocation, symptoms were recorded, and tears were collected with preweighed strips of filter paper (Schirmer strip). Each strip was placed into a tared tube containing fluid appropriate for the optimal preservation of the mediator to be measured. It was therefore possible to calculate the weight of tears collected and to express mediator levels per milliliter of tears. All allergic subjects demonstrated a positive symptomatic response to allergen challenge, whereas the control subjects remained asymptomatic. Blockage of the tear duct did not significantly alter the response. For allergic subjects, the levels of histamine, kinins, prostaglandin D2, albumin, and TAME-esterase activity were all significantly (p less than 0.005 in each case) greater after allergen challenge than after saline challenge. Furthermore, levels of each of these mediators after allergen challenge (expressed as increases above levels after saline provocation) were significantly greater for allergic subjects than for control subjects (p less than 0.005 in each case). Thus, the clinical response to conjunctival provocation with allergen is associated with increases in the levels of inflammatory mediators in tears.

Cross sensitivity with acetaminophen in aspirin-sensitive subjects with asthma.

Drugs inhibiting cyclooxygenase regularly cross-react with aspirin (ASA). Although some experiments suggest that acetaminophen (ACETM) is a weak inhibitor of cyclooxygenase in certain tissues, it has not been studied in human lung tissue, and controversy exists whether or not true cross-reactivity occurs between ASA and ACETM. Three ASA-sensitive subjects with asthma, who gave a history of reactions to ACETM, underwent double-blind, placebo-controlled challenges and reacted to 1000 mg of ACETM with a greater than 20% fall in FEV1. Two patients were desensitized to ASA and then were rechallenged with 1000 mg of ACETM without reaction. Two patients were desensitized to increasing doses of ACETM, achieving refractoriness to 1500 mg, but not 2000 mg. Thus, cross sensitivity between ASA and ACETM was documented when large challenge doses (1000 mg) of ACETM were used. Furthermore, cross desensitization suggests that in ASA-sensitive subjects with asthma, similar mechanisms are likely to be responsible for reactions to ASA, nonsteroidal anti-inflammatory drugs, and ACETM.

Pollen immunotherapy during pregnancy: long-term follow-up of offsprings.

The purpose of this study is to determine the long-term affect of maternal pollen immunotherapy on offsprings who are ten years or older. Records of two allergists were reviewed, identifying 63 consecutive pregnant patients who received allergy injections to pollens. Of these patients, 30 returned questionnaires and 23 qualified for this study. A total of 78 offsprings were evaluated. In 40 of these offsprings, (treated group) mean age 16, their mothers had received immunotherapy during pregnancy. In 38 control siblings (untreated offsprings), mean age 22, their mothers had not received immunotherapy during pregnancy. Data on offsprings were obtained by questionnaires and direct interview when skin tested (31% of offspring). Thirty-eight percent (15/40) of treated offsprings and 45% (17/38) of untreated offsprings developed asthma/allergic rhinitis. This difference is not statistically significant. Among the treated offsprings, 69% (9/13) of those skin tested had positive skin tests to one or more pollens administered to the mother while pregnant. Among the untreated offsprings (controls), 55% (6/11) of those skin tested had positive skin tests to one or more pollens administered to the mother during sibling pregnancy. This difference was not statistically significant. In summary, allergen immunotherapy in pregnancy does not appear to affect the development of asthma/rhinitis or positive skin tests in offsprings.

Aspirin intolerance and recurrent urticaria in normal adults and children. Epidemiology and review.

The frequency of aspirin intolerance by history in 2,592 normal individuals was 0.3%. Although the frequency of aspirin intolerance was similar in adults and children, the bronchospastic type predominated in adults, and only the urticarial type was found in normal children. The frequency of recurrent urticaria, regardless of etiology, was significantly greater in adults than in children (3.8% vs. 0.3, P less than 0.001). In adults the frequency of aspirin intolerance was over 20 times greater in individuals with recurrent urticaria than in normal individuals (6.5% vs. 0.3%, P less than 0.001).