Allergic rhinitis

Allergic and Nonallergic Rhinitis: Classification and Pathogenesis Part I. Allergic Rhinitis

Chronic rhinitis, although not life-threatening, substantially interferes with one's quality of life. Associated symptoms of nasal obstruction, sneezing, rhinorrhea, and anosmia afflict an estimated 40 million Americans. Directed clinical history and physical examination combined with noninvasive and routine procedures permit physicians to diagnose the myriad conditions causing rhinitis. Although the precise etiology of many of these conditions is only partially known, a practical diagnostic classification can be formulated based on clinical and laboratory findings. An understanding of the pathophysiology of allergic rhinitis as well as the other less understood entities provides the clinician with a integral foundation to implement preventative and therapeutic measures. This comprehensive review should provide the reader an opportunity to better understand and appreciate the causes and pathophysiology of chronic rhinitis. Part I of this article concentrates on IgE-mediated reactions, mediators, and drugs involved in allergic rhinitis. Part II focuses on the recent advances gained in understanding the nonallergic (non-IgE) causes of chronic rhinitis.

Mediators of Anaphylaxis, Anaphylactoid Reactions, and Rhinitis

Besides histamine, a large and increasing number of mediators of allergic reactions are being found to be released by mast cells or basophils during anaphylactic reactions. Many of these same substances are released by stimuli other than allergen-IgE interactions, and this type of phenomenon (anaphylactoid or pseudo-allergic reaction) may account for some nasal symptoms that simulate allergy. In addition to rapidly developing reactions of these types, numerous recent investigations have emphasized the importance of late-phase reactions that occur as a consequence of the immediate reactivity. Besides mast cells and/or basophils, these late effects seem to involve a complex network of cellular interactions, which may include neutrophils, eosinophils, lymphocytes, macrophages, and platelets.

Studies of nasal washings following allergen challenges in humans have provided cogent in vivo support of earlier hypotheses about mediator release based on in vitro experimentation.

Rhinitis, Sinusitis, and Their Relationships to Allergies

To investigate the relationship between allergic rhinitis and sinusitis, a review of all patients seen at an outpatient suburban otolaryngology clinic was performed. Three hundred ninety-three of the 1846 (21.3%) new patients seen over an 18-month period presented with nasal complaints. Ninety-two patients had documented allergy associated rhinitis. Thirty-seven patients had strong allergic histories without allergy testing. Two thirds had worsening nasal-sinus symptoms with allergen exposure; 82% of those with seasonal symptoms noted such a relationship compared with 32% of those with nonseasonal symptoms. There was 100% correlation of the onset of acute sinusitis with worsening allergies in the allergic group, although patients with chronic sinusitis and allergies noted worsening of sinusitis with allergen exposure in only 50%. Hyposmia/anosmia or asthma were good predictors of allergies in patients presenting with nasal or sinus complaints. Sixty percent of the confirmed allergic patients responded well to medical management alone. Patients with chronic sinusitis, with or without nasal polyps, tended to respond more poorly than did the entire group to medical management alone but did better with surgical therapy.

Histamine receptor type coupled to nitric oxide-induced relaxation of guinea-pig nasal mucosa

1 The aim of this study was to characterize the histamine receptor type mediating relaxation of the vascular bed of the nasal mucosa from the guinea-pig, and to determine the role of cyclo-oxygenase products and nitric oxide in this relaxant response to histamine. These studies were performed in isolated nasal mucosae examined in vitro to obtain potencies of histamine receptor-type selective agonists in causing vasorelaxation and to determine affinities of histamine receptor antagonists for inhibiting histamine-induced relaxation. 2 After contraction of nasal mucosae with noradrenaline, histamine caused a maximal relaxation response that was 75 +/- 6% of the contraction caused by noradrenaline with a mean EC50 value of 4.3 +/- 0.5 microM. Neither dimaprit (H2-receptor selective) nor R-alpha-methylhistamine (H3-receptor selective) caused significant relaxation of nasal mucosae. In contrast, betahistine (H1-receptor selective) caused an 81 +/- 7% relaxation of noradrenaline-induced tone with an EC50 value of 15 +/- 1 microM. 3 pA2 experiments were performed to obtain KB values of chlorpheniramine (H1-receptor selective) and diphenhydramine (H1-receptor selective) for blocking histamine-stimulated relaxation of nasal mucosae. KB values for chlorpheniramine (0.87 nM) and diphenhydramine (7.4 nM) were consistent with their interaction at the H1-receptor type. Additionally, neither 10 microM cimetidine (H2-receptor selective) nor 1 microM thioperamide (H3-receptor selective) had any effect on the relaxation curve for histamine. 4 In the presence of 10 microM indomethacin (cyclo-oxygenase inhibitor), histamine caused a maximal relaxation response of 73 +/- 5% of the noradrenaline-induced tone with an EC50 value of 2.9 +/- 0.2 microM, which was not different from control values (EC50 = 5.0 +/- 0.4 microM; maximal relaxation = 71 +/- 6%). In contrast, 200 microM NG-nitro-L-arginine (nitric oxide synthase inhibitor) completely inhibited histamine-induced relaxation of nasal mucosae. 5 In conclusion, data from the present study suggest only the H1-receptor type mediates relaxation of nasal mucosal blood vessels to histamine, and histamine-induced relaxation of nasal mucosae is entirely dependent on nitric oxide production.

Influence in the quality of life of the respiratory patients by environmental control and the acaricide Frontac®

The present prospective, open, observational study assessed the effect of the use of standard environmental control measures together with the application of an acaricide-containing aerosol of esbiol/benzyl benzoate/piperonyl butoxide/2-phenylphenol (Frontac) on several clinical and environmental parameters in patients suffering from perennial allergic rhinoconjunctivitis related to house dust mites (HDM). Fifty-five patients were enrolled and studied for one year. Both symptoms and the patients' quality of life (evaluated by the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ)) were assessed at several clinic visits. The amount of HDM antigen was semi-quantitatively estimated using the guanine test. We found a significant decrease (p < 0.001) in most nasal symptoms scores: sneezing, runny nose, stuffy nose and itching. The overall quality of life (QoL) score also showed a significant improvement during the study period; the mean score decrease found was 0.86 (CI 95 %, 0.54-1.17) (p < 0.001). Five of the seven domains included in the questionnaire decreased significantly: non-hayfever symptoms; practical problems; nasal symptoms; eye symptoms, and emotions. These QoL score decreases were found during the first 3 months and later remained stable at lower levels than at baseline. The content of guanine in dust samples decreased significantly from 2.17 0.75 to 1.43 0.68 (p < 0.001). No toxic adverse events were recorded. In conclusion, these results show an improvement in the quality of life and a clinical benefit of the long-term use of the new chemical acaricide tested, together with environmental measures, in the home of patients suffering from allergic respiratory pathology.

Comparison of ipratropium bromide 0.03% with beclomethasone dipropionate in the treatment of perennial rhinitis in children

OBJECTIVE

To compare the safety and efficacy of ipratropium bromide 0.03% (IB) with beclomethasone dipropionate 0.042% (BDP) in the treatment of perennial rhinitis in children.

METHODS

Thirty-three children with nonallergic perennial rhinitis (NAPR) and 113 with allergic perennial rhinitis (APR) were randomly assigned to either IB or BDP for 6 months in a single-blind, multicenter protocol in which the physician was blinded to treatment. At each visit, patients and physicians rated symptom control of rhinorrhea, nasal congestion, and sneezing. Patients also completed quality of life questionnaires at baseline and after 6 months of therapy.

RESULTS

Both treatments showed a significant improvement in control of rhinorrhea, congestion, and sneezing compared with baseline over the 6 months of treatment (P < .05). Only for the control of sneezing was BDP consistently better than IB (P < .05). Among the patients given IB, 61% to 73% assessed the control of rhinorrhea as good or excellent on different study visit days, 43% to 60% similarly rated the control of nasal congestion, and 39% to 43% the control of sneezing. The results for BDP were 68% to 78% for the control of rhinorrhea, 55% to 72% for the control of nasal congestion, and 54% to 68% for the control of sneezing. Quality of life assessment documented that both drugs significantly reduced interference with daily activities and disturbance of mood due to rhinorrhea compared with baseline (P < .05). Both treatments were well tolerated with IB causing less nasal bleeding and irritation than BDP.

CONCLUSIONS

Ipratropium bromide was safe and effective in controlling rhinorrhea and diminishing the interference by rhinorrhea in school attendance, concentration on school work, and sleep. Ipratropium bromide was as effective as BDP in the control of rhinorrhea and showed a relatively good effect on congestion. Patient and physician assessment favored BDP in the control of sneezing.

Acoustic rhinometry evaluation of nasal response to histamine and antigen in guinea pigs

The effects of antigen and histamine on the changes of nasal passage patency in 112 guinea pigs with or without allergic rhinitis were evaluated by acoustic rhinometry. The percent change of volume from the nostril to 2 cm into the nasal cavity showed significant reduction of 31.10 +/- 4.11% at 10 minutes and 31.10 +/- 4.11% at 30 minutes after antigen challenge in sensitized guinea pigs. The pretreatment with ketotifen, an H1-histamine receptor antagonist as well as mast cell stabilizing drug, blocked dose-dependently the effects of antigen on those changes in volume. Furthermore, instillation of 10(4) micrograms/mL histamine reduced significantly nasal passage patency to 33.77 +/- 4.63% at 10 minutes and 42.76 +/- 3.32% at 30 minutes after challenge compared with that before challenge and ketotifen inhibited the effects of histamine, which indicated that histamine is an important mediator of allergic upper airway responses in guinea pigs. These results show that acoustic rhinometry is a useful technique to assess the nasal blockade in allergic guinea pigs.

Diagnosis and management of rhinitis

This article reviews the differential diagnoses for rhinitis, medications available for the treatment of rhinitis, and special circumstances (such as pregnancy or medication side-effects) that may influence a clinician's decision. Considering the economic impact of rhinitis, the cost of prescription medications, and quality-of-life issues that are affected by rhinitis, physicians dealing with managed care organizations should make their diagnosis and treatment decisions carefully.

Diagnosis and management of rhinitis: complete guidelines of the Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology. American Academy of Allergy, Asthma, and Immunology

This document contains complete guidelines for diagnosis and management of rhinitis developed by the Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology, representing the American Academy of Allergy, Asthma and Immunology, the American College of Allergy, Asthma and Immunology and the Joint Council on Allergy, Asthma and Immunology. The guidelines are comprehensive and begin with statements on clinical characteristics and diagnosis of different forms of rhinitis (allergic, non-allergic, occupational rhinitis, hormonal rhinitis [pregnancy and hypothyroidism], drug-induced rhinitis, rhinitis from food ingestion), and other conditions that may be confused with rhinitis. Recommendations on patient evaluation discuss appropriate use of history, physical examination, and diagnostic testing, as well as unproven or inappropriate techniques that should not be used. Parameters on management include use of environmental control measures, pharmacologic therapy including recently introduced therapies and allergen immunotherapy. Because of the risks to patients and society from sedation and performance impairment caused by first generation antihistamines, second generation antihistamines that reduce or eliminate these side effects should usually be considered before first generation antihistamines for the treatment of allergic rhinitis. The document emphasizes the importance of rhinitis management for comorbid conditions (asthma, sinusitis, otitis media). Guidelines are also presented on special considerations in patients subsets (children, the elderly, pregnancy, athletes and patients with rhinitis medicamentosa); and when consultation with an allergist-immunologist should be considered.

Efficacy and onset of action of fluticasone propionate aqueous nasal spray on nasal symptoms, eosinophil count, and mediator release after nasal allergen challenge in patients with seasonal allergic rhinitis

We studied the effect and onset of action of fluticasone propionate aqueous nasal spray (FPANS) on mediator release and eosinophil accumulation in nasal secretions and on nasal symptoms of patients with seasonal allergic rhinitis after nasal allergen challenge (NAC). At the end of the pollen season, 28 patients were randomized in a double-blind and crossover design to receive 7 days' treatment with FPANS (200 microg, once daily) and matching placebo. NACs were performed before and at 6 h and 1, 2, 3, and 7 days during treatment with FPANS or placebo. Nasal secretions were collected for a quantitative determination of mediators and eosinophil count before and 5 min after each challenge. Nasal symptoms were assessed by scales grading the severity of symptoms at the same time. Results showed that for mediator concentrations there was a significant decrease of leukotriene C4 (P<0.001) at 7 days after the first administration of FPANS as compared to placebo. Two days after FPANS, both eosinophil counts and eosinophil cationic protein (ECP) concentrations were lower than those of placebo (eosinophils: P=0.032; ECP: P=0.038). The onset became even more important at day 7 (eosinophils: P=0.001; ECP: P=0.009) during the FPANS treatment period. For the subjective nasal symptoms, a significant reduction of symptom scores for nasal obstruction occurred also at day 3 (P=0.017) and for sneezing at day 7 (P=0.003). There was not yet any significant improvement of the objective nasal airway resistance after the different NACs during the study period. In conclusion, this study demonstrated that topical fluticasone propionate is effective in the treatment of mucosal inflammation induced by NAC. For optimal control of nasal symptoms induced by repeated maximal allergen challenges, a treatment period of more than 1 week is required.

Immunotherapy in patients undergoing functional endoscopic sinus surgery

A total of 283 consecutive patients with chronic sinusitis underwent functional endoscopic sinus surgery. There were 72 allergic patients and 211 nonallergic patients. Data were collected on the effect of immunotherapy on middle meatotomy patency, synechiae formation, and recurrent polyps in allergic patients. Data supported the following conclusions: (1) Immunotherapy given either before or after surgery does not statistically influence middle meatotomy patency, synechiae formation, or recurrence of polyps after functional endoscopic sinus surgery. However, the data do suggest, for all three outcome parameters, that allergic patients who undergo immunotherapy do better than those who do not undergo immunotherapy and, with the exception of recurrent polyps, do as well as nonallergic patients. (2) The prevalence of preoperative polyps is the same for allergic and nonallergic patients in this study, but polyp recurrence is higher in allergic patients. (3) Approximately 40% of allergic patients who began preoperative immunotherapy stopped immunotherapy after surgery because their allergic symptoms resolved or were minimal. A comment regarding this observation is provided.

Effects of immunotherapy with a purified standardized allergen preparation of Dermatophagoides farinae in adults with perennial allergic rhinoconjunctivitis

Immunotherapy (IT) was performed for 12 months with a purified and standardized preparation of Dermatophagoides farinae. Twenty adults with rhinoconjunctivitis sensitive to house-dust mite were given IT, and a similar group of 11 patients served as open controls. A total of 512 injections were given. Twenty-eight episodes of allergic side-effects occurred, 13 general and 15 local, most of them during the initial incremental dose period. No severe reactions started later than 30 min after the injection. One patient suffered anaphylactic shock. In this patient, specific antibodies fell immediately, followed by an increase within 1 week. The therapy group improved significantly in relation to the open controls in patients' subjective evaluation of symptoms (P < 0.028) and skin (P < 0.0001) and conjunctival (P < 0.001) sensitivity. Specific IgE increased in controls (P < 0.0001) but not in IT-treated patients during the "mite season"; that is, there was a significant difference in change during the observation period (P < 0.0001). There was also a difference in change of specific IgG between the groups during the first 4-5 months and the whole year (P < 0.0001), but not from 4-5 months to 12 months. In contrast to changes in antibody titers (IgG, P = 0.04), changes in conjunctival (P < 0.01) and especially skin sensitivity (P < 0.005) correlated well with subjective improvement. This implies that the skin prick test and the conjunctival test can be recommended for follow-up of IT.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral methylprednisolone acetate (Medrol Tablets) for seasonal rhinitis: examination of dose and symptom response

The authors compared the effect of several doses an oral corticosteroid on symptom profile and severity in ragweed hay fever. Thirty-one patients were randomized to receive 0, 6, 12, or 24 mg methylprednisolone (Medrol Tablets [MP], Upjohn, Kalamazoo, MI). A baseline week in which no treatment was given preceded the treatment comparison. At the end of this week, symptom diaries showed that most of the subjects were experiencing moderate or severe symptoms. The corticoid produced dose-related reduction in all symptoms. The difference between placebo and 24 mg MP was significant for all the symptoms monitored, except itching, which benefited marginally. With 6 mg MP, congestion, drainage, and eye symptoms showed significant drug-placebo differences but itching, running/blowing, and sneezing did not. Not all rhinitis symptoms responded equally to corticoid treatment. Those that responded least could reflect histamine effect, which was not effectively suppressed by low-dose, short-term corticoid treatment.

Allergic rhinitis. Helping patients lead an unrestricted life

Allergic rhinitis is a common, chronic disorder that responds well to treatment. Evaluation should begin with thorough history taking and be followed by a comprehensive treatment plan that includes avoidance measures, combination medical therapy, and allergen immunotherapy, when appropriate. The management objective should be to alleviate symptoms so that the patient can lead a normal, unrestricted life.

Hayfever in the United Kingdom

In the U.K. allergy to grass pollen is the single most important cause of seasonal allergic rhinoconjunctivitis (hayfever). The prevalence of the disease appears to be increasing, although the precise reasons for this are at present unknown. The introduction of non-sedating H1-selective antihistamine drugs and local corticosteroids has been an important therapeutic advance. Immunotherapy (desensitization) has a part to play in the treatment of hayfever unresponsive to anti-allergic medication but because of the danger of systemic reactions its use is limited to specialized centres.

Effects of one-year hyposensitization in allergic rhinitis. Comparison of two house dust mite extracts

In an open study, 21 patients suffering from chronic non-seasonal rhinitis and allergic to house mites (HDM) have been treated for 1 year with either a new extract (Pharmalagen; n = 10) or an allergoid, pyridine denatured, extract (Alavac; n = 11), both precipitated with AlOH3 (depot). The following investigations were performed before and after therapy: clinical scoring (for 4 weeks), quantified skin prick tests (SPT) and nasal provocation tests (NPT) with HDM, and determination in serum of HDM-specific IgE and IgG. Both groups were compared with six patients who remained untreated and underwent the same investigations. Hyposensitization with either extract induced an improvement in clinical scores (P less than 0.05), a decrease in SPT reactivity (Pharmalgen: P less than 0.001; Alavac: P less than 0.01), a marked increase in the nasal tolerance to HDM (P less than 0.001) and in HDM-specific IgG (P less than 0.001). In the group of untreated patients, all these parameters remained unchanged. Compared with the Alavac extract, the Pharmalgen extract was more active in decreasing SPT reactions (P less than 0.05) and inducing a HDM-specific IgG rise (P less than 0.05). Although both extracts induced some untoward allergic reactions, no adrenaline was used at any time during the study. These data suggest that hyposensitization with depot extracts of HDM can be considered a safe and active adjunct to the treatment of allergic rhinitis.

Management of allergic rhinitis: focus on intranasal agents

The clinical manifestations of allergic rhinitis are the result of an immune-mediated process after exposure of a sensitized individual to airborne allergens. The primary symptomatology includes nasal congestion, rhinorrhea, nasal and conjunctival pruritus, and sneezing. Principles of management include allergen avoidance, palliative therapy, immunotherapy, and pharmacotherapy. Oral decongestants stimulate alpha-adrenergic receptors in the nasal cavity, resulting in vasoconstriction and decreased edema. Oral antihistamines block histamine1 (H1) receptors, and may relieve rhinorrhea, sneezing, and nasal and conjunctival pruritus. Topical decongestants have a local effect on adrenergic receptors in the nasal mucosa, resulting in rapid, marked vasoconstriction. Intranasal corticosteroids inhibit mediator release from mast cells and basophils, and reduce edema of the nasal mucosa. Dexamethasone sodium phosphate, beclomethasone dipropionate, and flunisolide are currently available for intranasal administration. Cromolyn sodium inhibits allergen-induced degranulation and mediator release from sensitized cells, and is useful primarily as a prophylactic agent. Several agents, including the corticosteroids budesonide and flucortin butylester, the mast cell-stabilizing agent nedocromil sodium, the anticholinergic agent ipratropium bromide, and the H1 receptor antagonist levocabastine are being investigated for intranasal use in the management of allergic rhinitis.

Does the effect of immunotherapy last after termination of treatment? Follow-up study in patients with grass pollen rhinitis

In a previous study, 39 adults with grass pollen allergy were hyposensitized for approximately 2 1/2 years. Treatment was performed in a double-blind fashion with extract made from timothy grass--either Alutard SQ 20-component extract or a purified 2-component extract, including only the two major allergens Phl p V and VI. Standardized symptom + medicine scores and challenge tests demonstrated a clinical effect, most markedly in the group receiving 20-component extract. Six years after termination of treatment, 38 patients could be approached and 16 in each group were examined and repeated symptoms scoring during the subsequent season. When adjustment for variations in pollen counts were made, medicine + symptom scores stayed low during the follow-up period. Specific IgE-antibodies against timothy showed an increase to initial values during the same period, whereas total IgE antibodies remained low. Skin prick test reactions with timothy allergen tended to increase but were still smaller than before treatment. Retrospectively, the patients reported symptoms to have stabilized or even further decreased after termination of treatment, with no significant difference between groups. In conclusion, the clinical effect was still present more than 6 years after termination of treatment. Some in vitro parameters tended to return to pretreatment level. The spontaneous course of the disease in non-hyposensitized patients was not investigated.

A new rhinitis model using chemical mediators in rats

No good experimental model for studying rhinitis, has been hitherto available. In the present study, development of a new rhinitis model using chemical mediators was attempted, especially to establish an index of nasal congestion. Male Wistar rats were anesthetized with pentobarbital-Na. Nasal cavities were ventilated between both cannulae inserted into the nasopharynx and bilateral nostrils, with an artificial respirator. Intranasal resistance was recorded with a modification of a Konzett-Rössler apparatus as a change in ventilation overflow (VO). To provoke rhinitis, some mediators were inhaled into the nasal cavities with an ultrasonic nebulizer for 5 min. To assess the capillary permeability of the nasal mucosa, exudation of Evans blue was determined by injecting the dye before inhalations of mediators. Inhalation of histamine (0.01, 0.1, 0.3%), bradykinin (0.01, 0.1%) and ACh (0.3%) markedly increased VO, while inhalation of serotonin (0.01, 0.1, 0.3%) did not increase VO. Histamine, bradykinin and high concentration of ACh significantly increased the dye exudation in the nasal cavities, although serotonin did not. From the above results, it is concluded that 1) a new rhinitis model in which symptoms of nasal blockage and increased capillary permeability in nasal mucosa are quantitatively determined, was established, and 2) histamine- and bradykinin-inhalations can cause rhinitis-like symptoms, although serotonin-inhalation can not.

The effect of immunotherapy on bronchial hyperresponsiveness and eosinophil cationic protein in pollen-allergic patients

The effect of immunotherapy (IT) on bronchial response to histamine and on eosinophil cationic protein (ECP) in 40 birch pollen-allergic patients with a history of rhinoconjunctivitis and wheezing during the birch season was examined. Twenty patients started IT with birch extract (Pharmacia, Uppsala, Sweden) before the season. The other 20 patients were not treated with IT. Histamine-challenge tests were performed before, at the start, at pollen peak, at the end, and after the birch-pollen season. Blood samples for determination of ECP were collected at the same time. Skin prick tests and nasal provocation tests were also performed before and after the season. A significant increase in bronchial hyperresponsiveness was noted in the group treated with IT and in the untreated group during the season. The increase was greatest in the untreated group with the maximal difference between the two groups at the end of the pollen season (p less than 0.07). IT treatment was followed by significantly less medication and higher peak expiratory flow values. The levels of ECP increased during the season in untreated patients (p less than 0.05) but not in patients treated with IT. The ECP levels of patients from both groups correlated significantly with histamine sensitivity (p less than 0.001).

Tryptase levels in nasal-lavage fluid as an indicator of the immediate allergic response

To examine mast cell involvement in allergic rhinitis, levels of tryptase, a specific marker for mast cell activation, and histamine, a marker of mast cell and basophil activation, were measured in nasal-lavage fluid after nasal-allergen challenge. Twelve atopic subjects with allergic rhinitis and five nonatopic subjects were challenged with timothy grass or ragweed pollen at increasing doses of allergen. Tryptase and histamine levels were determined by an ELISA and radioenzyme assay, respectively; clinical responses were measured by assessment of sneezing, rhinorrhea, nasal congestion, and ocular tearing or itching. A positive clinical response was observed in seven of the atopic subjects and in none of the nonatopic subjects. Tryptase levels increased at least sevenfold higher than baseline levels in 100% of the atopic clinical responders and reached a maximum at the same dose of allergen where clinical symptoms were maximal. In contrast, histamine levels were only threefold or greater elevated in five of seven atopic clinical responders at this dose of allergen. (Histamine levels were lower in one subject and were only 50% higher in another subject than the corresponding baseline value.) Histamine levels and symptom scores were maximal at the same dose of allergen in only four of seven clinical responders. Overlap of peak mediator levels in subjects without a clinical response with those of the clinical responders occurred only in the case of histamine. Tryptase levels in nasal-lavage fluid appear promising as a useful indicator of allergic reactions and indicate that mast cell activation is the major factor in the immediate nasal-allergic response.

Nasal eosinophilia in children: its use in the nasal allergen provocation test

This pediatric cytological and clinical study aimed at assessing the value of nasal eosinophilia during nasal provocation tests for identifying an offending allergen. The population studied comprised 50 children aged from 4 to 18 yr; 39 of these had well-characterized allergic rhinitis, which in 21 cases was combined with asthma, and the remaining 11 had nonatopic chronic rhinitis. Nasal secretions, collected by nose blowing, were stained with May-Grünwald-Giemsa or Wright stain. The percentage of nasal eosinophils was obtained by examining the cells in the whole slides. Counts were carried out on secretions collected before challenge, after insufflation of saline solution (for verification), and 40 min after insufflation into each nostril of an allergen (housedust mite extract). The nasal provocation test was considered positive when insufflation of the allergen increased nasal eosinophilia by more than 10%, provided that the prechallenge proportion of eosinophils was less than 50%. No increase in specific bronchial resistance was noted. These results indicate that nasal provocation tests are safe, even in asthmatic children.

Diesel-exhaust particulates inoculated by the intranasal route have an adjuvant activity for IgE production in mice

Our previous study indicated that the IgE antibody responses in mice immunized with intraperitoneal injection of the antigens mixed with diesel-exhaust particulates (DEP) were higher than those in the animals immunized with the antigens alone. We examined the adjuvant activity of DEP inoculated by the intranasal route, i.e., the natural entrance of DEP. In 3-week interval immunization, the IgE antibody responses in mice immunized with intranasal inoculation of ovalbumin (OA) mixed with DEP were higher than responses in the animals immunized with OA alone. DEP had an adjuvant activity for anti-OA IgE antibody production, even in a small dose such as 1 micrograms administered with a 3-week interval. Also in 1-week interval immunization, the enhancing effect of DEP on anti-OA IgE antibody production was demonstrated when mice were immunized with intranasal inoculation of OA and DEP. The possibility cannot be excluded that DEP, which are kept buoyant in the environmental atmosphere of urban districts, may exert an adjuvant activity for IgE antibody production after being inhaled into the human body and have some relation to the mechanism of the outbreak of allergic rhinitis caused by pollens in Japan.

Histamine concentrations in nasal secretion and secretory activity in allergic rhinitis

The prerequisites for using the assayed histamine concentration in nasal secretion as an objective measure of disease activity in allergic rhinitis were investigated. It was demonstrated that in histamine determination procedures the presence of quenching substances in the nasal secretion could lead to underestimation of the histamine concentration. This bias was eliminated in a modified spectrofluorometric assay. Only an insignificant fraction of the histamine in samples collected by nasal spray washing was bound to unfiltrable particles or cells. The mean histamine concentration in nasal secretions from 15 healthy subjects was 11.2 micrograms/ml and in a group of nine patients with allergic rhinitis out of season 3.36 micrograms/ml. The histamine concentration in the latter group decreased during the pollen season and after positive allergen challenge. It is suggested that this decrease is caused by the increase in volume of the secretion during the allergic response. The use of lithium as an exogenous marker permitted quantitation of the increase in the relative amount of nasal secretion recovered by washing in the symptomatic subjects.

Allergic rhinitis. A useful guide to diagnosis and treatment

Patients presenting with typical signs and symptoms of allergic rhinitis may respond to avoidance of allergens and to medications for symptomatic relief. Treatment may include antihistamines, decongestants, cromolyn sodium, and/or topical nasal steroids. Patients whose symptoms are refractory to these therapeutic measures should be referred to an allergist for further evaluation and consideration for possible allergen immunotherapy.

Low dose sublingual therapy in patients with allergic rhinitis due to house dust mite

In a double-blind placebo-controlled cross-over trial, low dose sublingual therapy with house dust mite was effective in relieving symptoms in 72% of the group of patients with perennial rhinitis due to house dust mite (P less than 0.03). Following active treatment, there was a significant increase in morning peak nasal inspiratory flow rate (P less than 0.01) in those who improved (thirteen out of eighteen) and resistance to nasal provocation with house dust mite also increased, in some cases up to 1000-fold (P less than 0.05). Oral therapy is safe and avoids the side effects of desensitizing injections which can be serious. The potential for oral desensitization is great and further studies on this form of treatment are needed.

Allergic Rhinitis and Sinusitis

Allergic rhinitis may often be satisfactorily managed by antihistamines, decongestants, and topical corticosteroids. When these simple methods fail, specific diagnosis and injection treatment (immunotherapy) by the specialist in allergy and immunology are in order.