Cystic fibrosis presenting with sinus disease in children

Chronic and Recurrent Sinusitis in Children, as Manifestation of Immune Dysfunction and Atopic Background

Rhinosinusitis in children, as in adults, can be classified by duration (acute, recurrent, and chronic) and by cause (viral, bacterial, and inflammatory) and needs to be treated accordingly after careful investigation which include through clinical history, laboratory tests, and, if necessary, nasal endoscopy and imaging studies.

Sinus hypoplasia precedes sinus infection in a porcine model of cystic fibrosis

OBJECTIVES/HYPOTHESIS

Chronic sinusitis is nearly universal in humans with cystic fibrosis (CF) and is accompanied by sinus hypoplasia (small sinuses). However, whether impaired sinus development is a primary feature of loss of the cystic fibrosis transmembrane conductance regulator (CFTR) or a secondary consequence of chronic infection remains unknown. Our objective was to study the early pathogenesis of sinus disease in CF.

STUDY DESIGN

Animal/basic science research.

METHODS

Sinus development was studied in a porcine CF model.

RESULTS

Porcine sinus epithelia expressed CFTR and exhibited transepithelial anion transport. Disruption of the CFTR gene eliminated both. Sinuses of newborn CF pigs were not infected and showed no evidence of inflammation, yet were hypoplastic at birth. Older CF pigs spontaneously developed sinus disease similar to that seen in humans with CF.

CONCLUSIONS

These results define a role for CFTR in sinus development and suggest the potential of the CF pig as a genetic model of CF-sinus disease in which to test therapeutic strategies to minimize sinus-related CF morbidity.

Pediatric sinusitis

Although sinusitis is one of the most common problems encountered in clinical practice, it can be a challenge to diagnose and treat appropriately. Sinusitis refers to inflammation (infectious or noninfectious) in the paranasal sinuses. Infectious sinusitis can be bacterial or viral. This article focuses on bacterial sinusitis. Acute bacterial sinusitis usually follows a viral upper respiratory infection (URI) but can also present with severe symptoms 3 to 5 days after onset. Chronic sinusitis has less prominent symptoms and can be easily missed. When antibiotic therapy is warranted, the antibiotic should be chosen based on knowledge of antimicrobial resistance in specific geographic areas and populations. Adjunctive measures include saline irrigation, steam inhalation, nasal and systemic steroids, mucolytics, and decongestants. It is important to identify and treat predisposing factors, including viral URIs, allergic rhinitis, nasal structural abnormalities, gastroesophageal reflux disease, and immune deficiencies.

Nasal potential difference measurements in patients with atypical cystic fibrosis

The diagnosis of cystic fibrosis (CF) is based on characteristic clinical and laboratory findings. However, a subgroup of patients present with an atypical phenotype that comprises partial CF phenotype, borderline sweat tests and one or even no common cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The aim of this study was to evaluate the role of nasal potential difference (PD) measurements in the diagnosis of CF patients with an atypical presentation and in a population of patients suspected to have CF. Nasal PD was measured in 162 patients from four different groups: patients with classical CF (n = 31), atypical phenotype (n = 11), controls (n = 50), and patients with questionable CF (n = 70). The parameter, or combination of nasal PD parameters was calculated in order to best discriminate all CF patients (including atypical CF) from the non-CF group. The patients with atypical CF disease had intermediate values of PD measurements between the CF and non-CF groups. The best discriminate model that assigned all atypical CF patients as CF used: e(response to chloride-free and isoproterenol/response to amiloride) with a cut-off >0.70 to predict a CF diagnosis. When this model was applied to the group of 70 patients with questionable CF, 24 patients had abnormal PD similar to the atypical CF group. These patients had higher levels of sweat chloride concentration and increased rate of CFTR mutations. Nasal potential difference is useful in diagnosis of patients with atypical cystic fibrosis. Taking into account both the sodium and chloride transport elements of the potential difference allows for better differentiation between atypical cystic fibrosis and noncystic fibrosis patients. This calculation may assist in the diagnostic work-up of patients whose diagnosis is questionable.

Sinusitis in patients with cystic fibrosis

The management of sinus disease in children with cystic fibrosis is reviewed, based on a literature review and clinical experience in The Hospital for Sick Children, Toronto. Diagnostic and treatment approaches are discussed, with emphasis given to indications for surgical therapies. Great importance is given to the preservation of normal nasal anatomy whenever possible to minimize the possibility of iatrogenic injuries occurring, especially when revision surgery is required.