Clinical and therapeutic aspects of sinusitis in children with bronchial asthma

Pediatric rhinosinusitis and asthma

Both asthma and rhinosinusitis are complex and heterogeneous diseases and, importantly, they often coexist: these diseases can be concomitant in 35-65% of affected children, according to different studies. Thus, evaluating this comorbidity in the clinical practice should be paramount. In this review, we focused our discussion on the multiple pathophysiological aspects that may link rhinosinusitis and asthma in the pediatric population. Although rhinosinusitis may exacerbate asthma through several mechanisms occurring by contiguity, actually this aspect seems to be only one component of the complex interplay between upper and lower airways. In particular, the onset of an important and persistent Th2-driven inflammatory process dominated by eosinophils presence at one site of the airways, may release into the bloodstream several cytokines; in their turn, those can lead to the stimulation of the bone marrow, which may function as a systemic amplifier of such an eosinophilic inflammation.

Association of Allergic Rhinitis and Sinusitis with Childhood Asthma

OBJECTIVE

To study the point prevalence of allergic rhinitis and sinusitis in childhood asthma and to examine the relationship among them.

METHODS

In 250 children (age <13 y) with mild-to-moderte asthma, allergic rhinitis was diagnosed by clinical plus nasal eosinophilia criteria, and sinusitis was diagnosed clinically plus confirmation by computerized tomography scan.

RESULTS

The point prevalence of allergic rhinitis was 13.6%, and of sinusitis was 2%. On multivariate analysis, allergic rhinitis, sinusitis, and family history were significantly associated with asthma severity.

CONCLUSION

Allergic rhinitis is common in childhood asthama, but sinusitis is rare.

Sinus and adenoid inflammation in children with chronic rhinosinusitis and asthma

BACKGROUND

Chronic rhinosinusitis (CRS) and asthma frequently coexist in children and adults. However, the precise pathophysiologic mechanism of this interaction is still poorly understood, especially in children, owing to the lack of direct measurements of mucosal inflammation in the upper airways.

OBJECTIVE

To determine the pathophysiologic mechanism by analyzing the expression of a large array of inflammatory cytokines and chemokines in the sinus and adenoid tissues surgically removed from pediatric patients with CRS refractory to medical management.

METHODS

Twenty-eight children 2 to 12 years old diagnosed with CRS with or without asthma and 10 controls were included in this prospective, nonrandomized study. Mucosal expression of 40 inflammatory cytokines was measured with a multiplex assay and was normalized to total tissue protein.

RESULTS

Compared with children with CRS and without asthma, children with CRS and asthma had significantly higher sinus levels of tumor necrosis factor-α and adenoid levels of epidermal growth factor, eotaxin, fibroblast growth factor-2, growth-related oncogene, and platelet-derived growth factor-AA.

CONCLUSION

The inflammatory response in the upper airway mucosa of children with asthma and CRS was similar, but more severe, compared with children with CRS without asthma. This observation is consistent with the hypothesis that asthma in these patients is caused or exacerbated by severe upper airway disease and supports the concept that treating sinus disease is paramount in the management of chronic asthma in children using, for the first time, direct measurements of airway inflammation in children.

Decongestants, antihistamines and nasal irrigation for acute sinusitis in children

BACKGROUND

The efficacy of decongestants, antihistamines and nasal irrigation in children with clinically diagnosed acute sinusitis has not been systematically evaluated.

OBJECTIVES

To determine the efficacy of decongestants, antihistamines or nasal irrigation in improving symptoms of acute sinusitis in children.

SEARCH METHODS

We searched CENTRAL (2014, Issue 5), MEDLINE (1950 to June week 1, 2014) and EMBASE (1950 to June 2014).

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs, which evaluated children younger than 18 years of age with acute sinusitis, defined as 10 to 30 days of rhinorrhea, congestion or daytime cough. We excluded trials of children with chronic sinusitis and allergic rhinitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed each study for inclusion.

MAIN RESULTS

Of the 662 studies identified through the electronic searches and handsearching, none met all the inclusion criteria.

AUTHORS' CONCLUSIONS

There is no evidence to determine whether the use of antihistamines, decongestants or nasal irrigation is efficacious in children with acute sinusitis. Further research is needed to determine whether these interventions are beneficial in the treatment of children with acute sinusitis.

Decongestants, antihistamines and nasal irrigation for acute sinusitis in children

BACKGROUND

The efficacy of decongestants, antihistamines and nasal irrigation in children with clinically diagnosed acute sinusitis has not been systematically evaluated.

OBJECTIVES

To systematically review the efficacy of decongestants, antihistamines and nasal irrigation in children with clinically diagnosed acute sinusitis. We considered the following four interventions: 1) decongestants versus placebo or no medication, 2) antihistamines versus placebo or no medication, 3) decongestant and antihistamine combination versus placebo or no medication, 4) nasal irrigation versus no irrigation. The primary outcomes of the review were symptom resolution (improvement in symptom score from enrolment to day five and overall symptom burden (as measured by average symptom scores while on therapy).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2012, Issue 1), which includes the Acute Respiratory Infections Group's Specialized Register, MEDLINE (1950 to January week 3, 2012) and EMBASE (1950 to January 2012).

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs which evaluated children less than 18 years of age with acute sinusitis, defined as 10 to 30 days of rhinorrhea, congestion or daytime cough. We excluded trials of children with chronic sinusitis and allergic rhinitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed each study for inclusion.

MAIN RESULTS

Of the 526 studies found through the electronic searches and handsearching, none met all the inclusion criteria.

AUTHORS' CONCLUSIONS

There is no evidence to determine whether the use of antihistamines, decongestants or nasal irrigation is efficacious in children with acute sinusitis. Further research is needed to determine whether these interventions are beneficial in the treatment of children with acute sinusitis.

Decongestants, antihistamines and nasal irrigation for acute sinusitis in children

BACKGROUND

The efficacy of decongestants, antihistamines and nasal irrigation in children with clinically diagnosed acute sinusitis has not been systematically evaluated.

OBJECTIVES

To systematically review the efficacy of decongestants, antihistamines and nasal irrigation in children with clinically diagnosed acute sinusitis. We considered the following four interventions: 1) decongestants versus placebo or no medication, 2) antihistamines versus placebo or no medication, 3) decongestant and antihistamine combination versus placebo or no medication, 4) nasal irrigation versus no irrigation. The primary outcomes of the review were symptom resolution (improvement in symptom score from enrolment to day 5) and overall symptom burden (as measured by average symptom scores while on therapy).

SEARCH STRATEGY

We searched the Cochrane Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2010), which includes the Acute Respiratory Infections Group's Specialized Register, MEDLINE (1950 to May Week 1, 2010) and EMBASE (1950 to January 2010).

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs which evaluated children less than 18 years of age with acute sinusitis, defined as 10 to 30 days of rhinorrhea, congestion or daytime cough. We excluded trials of children with chronic sinusitis and allergic rhinitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed each study for inclusion.

MAIN RESULTS

Of the 402 studies found through the electronic searches and handsearching, none met all the inclusion criteria.

AUTHORS' CONCLUSIONS

There is no evidence to determine whether the use of antihistamines, decongestants or nasal irrigation is efficacious in children with acute sinusitis. Further research is needed to determine whether these interventions are beneficial in the treatment of children with acute sinusitis.

The role of sinus disease in asthma

PURPOSE OF REVIEW

Some time ago, a link between upper and lower respiratory disease was described, which gave rise to the concept of 'united airways disease'. This concept primarily refers to the well established link between allergic rhinitis and asthma, but it also covers a possible link between sinus disease and asthma (allergic or nonallergic) and other lower airway disease.

RECENT FINDINGS

The current classification of chronic rhinosinusitis (CRS) includes disease without and with nasal polyps, which are considered subgroups of CRS. Different patterns of inflammatory and regulatory cytokines (involving distinguishable T-helper lymphocyte populations) and of remodelling markers, however, were recently described to differentiate nasal polyposis from CRS, yielding two discrete entities. These patterns resemble those of lower airway diseases, such as asthma and chronic obstructive pulmonary disease, and suggest a common aetiological/pathogenetic background. Whereas the link between nasal polyps and asthma is well established (indeed, asthma improves after medical or surgical treatment of sinus disease), that between CRS and lower airway disease is not well understood. Recently, Staphylococcus aureus enterotoxins, acting as superantigens, were identified as a possible link between nasal polyps and asthma, resulting in severe disease manifestations in both upper and lower airways.

SUMMARY

The role played by sinus disease in asthma is only partially understood, largely because of deficits in the clinical classification and in basic knowledge of pathophysiological pathways. Recent research into upper airway and sinus inflammation and remodelling may reveal new perspectives and lead to a classification of sinus disease, which will facilitate appropriate clinical and epidemiological studies.

Is rhinosinusitis a cause of asthma?

There is a great deal of evidence of an association between rhinosinusitis and asthma. However, it is less clear whether rhinosinusitis is a direct trigger for asthma or the two conditions are simply manifestations of a common underlying process. Evidence for a role for rhinosinusitis as a trigger for asthma includes many examples of improvement in asthma once concomitant rhinosinusitis is treated medically or surgically. Possible mechanisms for this relationship include naso-pharyngo-bronchial reflexes, postnasal drip, abnormal breathing, and the local production of inflammatory mediators that trigger pulmonary inflammation via the bone marrow. On the other hand, evidence exists that rhinosinusitis and asthma are manifestations of a common process. For example, there are similarities between the histopathological changes in the epithelium in chronic rhinosinusitis and asthma. The bone marrow may provide the link between the upper and lower airways in creating a common disease. A second possible mechanism for a common disease is response to staphylococcal enterotoxins. Although evidence exists to suggest that rhinosinusitis either triggers asthma or represents a local manifestation of a shared disorder, the key to reconciling this apparent controversy is to consider that rhinosinusitis is not just a single, uniform disease. Current evidence suggests that rhinosinusitis with neither polyps nor eosinophilic inflammation acts as a direct trigger for asthma, whereas rhinosinusitis with both polyps and eosinophilic inflammation shares underlying mechanisms with asthma. Clearly, however, there is considerable overlap between the different, complex mechanisms that link rhinosinusitis to asthma.

Rhino-bronchial syndrome in children: pathogenic correlations and clinical-experimental aspects

OBJECTIVE

This study aims at defining the incidence of rhino-bronchial syndrome (RBS) in children in order both to verify the influence of nasal obstructions on the disease and to determine therapeutic strategies which may cure the syndrome effectively at its early stage.

METHODS

The investigation includes 128 non-allergic children with obstructive disorders (adenoid hypertrophy, septal deviation, etc.) and rhino-sinus inflammations associated with bronchopulmonary diseases (asthma, chronic cough, bronchopulmonary infections). Medical and/or surgical treatment was chosen in consideration of the type and entity of the patients' main nasal pathology. At least 1 year follow-up was provided for each case to establish the improvement in the disorders affecting both the lower and upper airways. The results were statistically assessed.

RESULTS

Medical and mainly surgical treatment always cured the upper airways disorders in patients with chronic nasal obstruction and rhino-sinus inflammation. Improvement of bronchopulmonary disease was reported in about half of the patients (49.4%). Statistically significant results were obtained only in the group with recurrent bronchopulmonary infections (80.9%, p<0.05).

CONCLUSIONS

The study confirms that RBS may be quite frequent in childhood. This disorder has a multifactorial pathogenesis prevalently due to nasal obstruction and rhino-sinus infections. In the population studied, among the lower airways disorders, only infective bronchopulmonary inflammation showed a significant correlation in the assessment between lower and upper airways disorders. In order to prevent the progression of the syndrome to serious pathologic events of the lower airways, a prompt and effective treatment of children's nasal disorders is thus recommended.

Does post-nasal drip cause cough in childhood?

The proposition that post-nasal drip (PND) is a common cause of cough in childhood is controversial. The concept of PND as a common cause of cough is derived primarily from the adult literature. The definition of what constitutes PND is variable and it is unclear whether it is a symptom, a sign or both. Examination of the specificity of symptoms and signs for the diagnosis of PND syndrome further confuses the issue. A definitive diagnosis of cough induced by PND cannot be made from history and physical examination alone. The concept is inconsistent both with the meaning of the word 'drip' and the science of rheology. The most plausible explanation for the occurrence of cough in children identified with increased post-nasal secretions is that both reflect co-existent airways pathologies. In considering causes of chronic cough in childhood, it is now time to abandon the concept of PND and the associated PND syndrome.

Rhinosinusitis and pediatric asthma

Rhinosinusitis is a common disease in patients of all age groups. Rhinosinusitis arises from a variety of infectious and inflammatory mechanisms. There is ample evidence that rhinosinusitis can directly influence asthma. There is also growing evidence that rhinosinusitis may be associated with asthma as different manifestations of the same disorder. A great deal of future research is required to fully elucidate the different mechanisms whereby rhinosinusitis influences or associates with asthma, but it is clear that rhinosinusitis needs to be considered in patients with severe or refractory asthma.

Allergic rhinitis in children : diagnosis and management strategies

The incidence of allergic rhinitis has been increasing for the last few decades, in keeping with the rising incidence of atopy worldwide. Allergic rhinitis has a prevalence of up to 40% in children, although it frequently goes unrecognized and untreated. This can have enormous negative consequences, particularly in children, since it is associated with numerous complications and comorbidities that have a significant health impact on quality of life. In fact, allergic rhinitis is considered to be a risk factor for asthma. There are numerous signs of allergic rhinitis, particularly in children, that can alert an observant clinician to its presence. Children with severe allergic rhinitis often have facial manifestations of itching and obstructed breathing, including a gaping mouth, chapped lips, evidence of sleep deprivation, a long face, dental malloclusions, and the allergic shiner, allergic salute, or allergic crease. The medical history is extremely important as it can reveal information regarding a family history of atopy and the progression of atopy in the child. It is also important to identify the specific triggers of allergic rhinitis, because one of the keys to successful management is the avoidance of triggers. A tripartite treatment strategy that embraces environmental control, immunotherapy, and pharmacologic treatment is the most comprehensive approach. Immunotherapy has come to be viewed as potentially prophylactic, capable of altering the course of allergic rhinitis. The most recent guidelines for the management of allergic rhinitis issued by the WHO recommend a tiered approach that integrates diagnosis and treatment, in which allergic rhinitis is subclassified both by frequency, as either intermittent or persistent, and by severity, as either mild or moderate to severe. Oral or topical antihistamines and intranasal corticosteroids are the mainstay of pharmacologic therapy for allergic rhinitis, depending upon its severity, and several agents have been approved for use in children aged 5 years old and younger.

The epidemiology of chronic rhinosinusitis in Canadians

OBJECTIVE

To study the prevalence of chronic rhinosinusitis and its risk factors among Canadians.

STUDY DESIGN

Complex survey design incorporating stratification, multiple stages of selection, and unequal probabilities of selection of respondents.

METHODS

We used the cross-sectional data from 73,364 subjects (34,241 male and 39,123 female subjects) 12 years of age or older who participated in the second cycle of the National Population Health Survey, which was conducted from 1996 to 1997. All these individuals were asked whether they had certain chronic health conditions that had lasted or were expected to last 6 months or longer, including rhinosinusitis.

RESULTS

The prevalence of rhinosinusitis was higher in female (5.7%) than in male (3.4%) subjects. The sex difference was consistent across age groups. The prevalence increased with age and leveled off after the age of 60 years. In female but not in male subjects, the prevalence was slightly higher among those living the eastern region or among native Canadians as compared with those living in the central or western regions or immigrants. Cigarette smoking and low income were associated with a higher prevalence of rhinosinusitis in both sexes. The smoking effect was modified by allergy history in male subjects. Rhinosinusitis was more common among subjects with allergy history, asthma, or chronic obstructive pulmonary disease. The prevalence of rhinosinusitis was similar in subjects with or without reporting regular alcohol drinking and exercise.

CONCLUSION

Previous data indicating an increased susceptibility of women to asthma and chronic obstructive pulmonary disease, together with the similar finding for rhinosinusitis, suggest that women have a general increase in susceptibility to respiratory tract disease.

Improvement of clinical and immunopathologic parameters in asthmatic children treated for concomitant chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis is frequently associated with asthma. A Th2 cytokine pattern has been recently reported in chronic rhinosinusitis in asthmatic children.

OBJECTIVE

To evaluate the effects of treating concomitant chronic rhinosinusitis on respiratory symptoms and function and immunopathological parameters in asthmatic children.

METHODS

Eighteen children with moderate asthma (age range, 5 to 12 years) poorly controlled by high doses of inhaled corticosteroids and chronic rhinosinusitis were evaluated for symptoms, spirometry, and inflammation at baseline, after treatment, and 1 month after suspension of treatment. All of the children were treated with a combination of amoxicillin and clavulanate (20 mg/kg twice daily) and fluticasone propionate aqueous nasal spray (100 microg/d) for 14 days. A short course of oral corticosteroids was also prescribed (deflazacort, 1 mg/kg daily for 2 days, 0.5 mg/kg daily for 4 days, and 0.25 mg/kg daily for 4 days). Rhinosinusal lavage for cytokine measurements and a nasal scraping for cytologic analysis were performed in all patients before and after medical treatment.

RESULTS

A negative endoscopy result was demonstrated in 15 children after treatment. Symptoms and respiratory function significantly improved after treatment and 1 month later; 8 children had intermittent asthma and 10 had mild asthma. A significant reduction of inflammatory cell numbers was detected in all asthmatic children. Interleukin 4 levels significantly decreased (P < 0.001), whereas interferon-y levels increased (P < 0.001).

CONCLUSION

Treatment of chronic rhinosinusitis is able to improve symptoms and respiratory function in asthmatic children, reducing inflammatory cells and reversing the cytokine pattern from a Th2 toward a Th1 profile.

Cytokine pattern in allergic and non-allergic chronic rhinosinusitis in asthmatic children

BACKGROUND

Rhinosinusitis represents one of the most common chronic diseases. The association of rhinosinusitis with asthma has been frequently reported. Eosinophils and Th2 cells play a pathogenic mechanism in asthma.

OBJECTIVE

The aims of the study were to evaluate the cytokine pattern in chronic rhinosinusitis in asthmatic children and to compare the findings in allergic vs. non-allergic asthmatics.

METHODS

Thirty-five asthmatic children were evaluated, 19 males and 16 females, with an average age of 8.7 years. All children were asthmatic and suffered from chronic rhinosinusitis. Twenty were allergic and 15 were non-allergic. Ten healthy children were studied as normal controls. Evaluated parameters were the levels of the following cytokines: IL-1beta, IL-4, IL-6, IL-8, IL-12, IFN-gamma and TNF-alpha. Cytokines were recovered from rhinosinusal lavage and measured by immunoassays. Nasal cytology was also performed in all subjects and inflammatory cells were counted by conventional staining.

RESULTS

Allergic subjects showed a significant increase of IL-4 (P < 0.01) and TNF-alpha (P < 0.05) and a significant decrease of IL-12 (P < 0.05) and of IFN-gamma (P < 0.0001), whereas IL-1beta, IL-6 and IL-8 were not significantly increased. Non-allergic children showed a significant increase of IL-4 (P < 0.05) and a significant decrease of IFN-gamma (P < 0.0001), IL-12 was not significantly decreased, and IL-1beta, IL-6 and IL-8 were not significantly increased. A significant inflammatory infiltrate was present in all asthmatic children. Significant correlations were demonstrated between IL-4 and IL-12 (P < 0.001), IL-12 and IFN-gamma (P < 0.001), IL-8 and neutrophils (P < 0.01), and TNF-alpha and monocytes/macrophages (P < 0.05), in allergic asthmatics. IL-4 and IL-12 were significantly correlated (P < 0.05) as well as IL-8 and neutrophils (P < 0.01) in non-allergic asthmatics.

CONCLUSION

This study shows that allergic asthmatic children with chronic rhinosinusitis have a typical Th2 cytokine pattern, but also non-allergic asthmatic children share a similar pattern. These findings would suggest the existence of a common pathophysiological mechanism shared by upper and lower airways and are consistent with the concept of united airways disease.

Nasal endoscopy in asthmatic children: assessment of rhinosinusitis and adenoiditis incidence, correlations with cytology and microbiology

BACKGROUND

Upper respiratory airway diseases may induce a worsening of asthma. Sinusitis represents one of the most common chronic diseases. The association of asthma and sinusitis varies greatly in different studies, depending on diagnostic procedures.

OBJECTIVE

The aims were: (i) to demonstrate that nasal endoscopy may be easily feasible in asthma at paediatric age; (ii) to evaluate the incidence of rhinosinusitis and adenoiditis in children with asthma by nasal endoscopy; (iii) to correlate inflammatory parameters such as cytology and microbiological cultures with nasal endoscopy findings.

SUBJECTS AND METHODS

One hundred and forty-five asthmatic children were evaluated, 48 males and 97 females, with an average age of 7.27 years. Evaluated parameters were the incidence of rhinosinusal infections in asthmatic children, and the role of: (i) nasal endoscopy, (ii) nasal cytology, and (iii) nasal microbiology in their diagnoses.

RESULTS

Nasal endoscopy was successfully performed on 128 patients. Twenty-six children had endoscopic rhinosinusitis alone, 10 had adenoiditis alone, and 35 showed endoscopic rhinosinusitis associated with adenoiditis. There were significant correlations between endoscopic rhinosinusitis and adenoiditis (P < 0.001), between clinical and endoscopic rhinosinusitis (P < 0.001), between endoscopic rhinosinusitis and adenoiditis and microbiology (P < 0.05 and P < 0.0001, respectively), and between microbiology and cytology (P < 0.05).

CONCLUSION

This study shows that rhinosinusal infections are common in asthmatic children. Moreover, nasal endoscopy might represent a fruitful tool in the management of asthmatic children.

The relation between physician-diagnosed sinusitis, asthma, and skin test reactivity to allergens in 8-year-old children

The purpose of this study was to assess the prevalence of sinusitis in a nonselected sample of children, and the relation of sinusitis to allergic rhinitis (AR), atopy, asthma, and cough in the same population sample. Of 1246 children enrolled at birth in the Tucson Children's Respiratory Study, 835 were studied at a mean age +/-SD of 8.6 +/- 0.7 years. Questionnaires asking about MD-Sinusitis, MD-AR, MD-Asthma, and cough were completed by parents. Skin tests for seven common aeroallergens in the Tucson area had been performed in 630 of the participating children at the mean age +/-SD of 6.3 +/- 0.9 years. Prevalence of MD-Sinusitis was 13.1%; 78% of subjects with MD-Sinusitis also had MD-AR. Detailed analysis of the relation between MD-Sinusitis and individual environmental allergens tested for showed that only a response to Bermuda grass pollen was significantly associated with MD-Sinusitis after controlling for MD-AR [adjusted odds ratio 2.3 (95% CI 1.2-4.3)]. Having MD-Sinusitis was also significantly associated with MD-Asthma and cough [odds ratios 3.0 (95% CI 1.8-5.2)] and 2.5 (95% CI 1.6-3.8), respectively]. However, logistic regression demonstrated that, after controlling for MD-AR and skin test reactivity, MD-Sinusitis was no longer significantly associated with MD-Asthma or cough. We conclude that MD-Sinusitis is a common condition in childhood. The main independent risk factors in our community for MD-Sinusitis were grass pollen and current MD-AR. MD-Sinusitis was not associated with MD-Asthma or with cough after controlling for skin test reactivity and for MD-AR.

Increased lower airways responsiveness associated with sinusitis in a rabbit model

The association between sinusitis and asthma has been clinically recognized, but its precise nature is controversial. We studied the relationship between sinusitis and lower airways function in a rabbit model of sterile maxillary sinusitis induced by the chemotactic complement fragment C5a des arg. Animals kept in a head-up position following experimental sinusitis demonstrated a significant increase in airways responsiveness (AWR) to histamine. In contrast, animals of which the sinuses were injected with a saline diluent and in which no sinus inflammation developed had no increase in AWR. Experiments were subsequently carried out to investigate some of the potential mechanisms for these observations. A group of rabbits in which a distal site of inflammation was induced did not demonstrate increased AWR. Likewise, when sinus inflammation was established but passage of fluid to the lower airways was prevented, either by intubation or by head-down positioning, there was no change in AWR. A fourth experiment was designed to decrease complement factor activity before placing the animals in a head-up position. This led to the same degree of increased AWR. Neither the histology nor the bronchoalveolar lavage data demonstrated significant lower airways inflammation in any group. We conclude that sterile sinusitis can increase lower airways responsiveness to histamine in a rabbit model. The most likely mechanism for this effect is the postnasal dripping of cells or cell products into the lower airway. The role of a nasobronchial reflex or inflammatory mediator absorption could not be demonstrated in this model.

Complicating features of asthma

The recognition of factors other than asthma that make asthma worse, are confused with asthma, or occur concurrently with asthma and may or may not interact with asthma is as important as dealing with the asthma itself. In this article I have tried to give an overview of some of these factors: what they are, how they affect patients with asthma, and what to do about them. The recognition of a covert chronic sinusitis, for example, is often key to controlling a person's disease when it appears that everything is being done appropriately. Close attention to these factors will increase the success of treatment of asthma and improve the quality of life of patients.