Implementation of a screening tool for primary ciliary dyskinesia (PCD) in a pediatric otolaryngology clinic

Abstract

Background: Primary ciliary dyskinesia (PCD) is a rare genetic disease arising from motile ciliary dysfunction and associated with recurrent and chronic upper and lower respiratory tract infections. Pediatric otolaryngologists may see these patients prior to the development of lung disease. Features of PCD may overlap with other suppurative respiratory diseases, creating diagnostic challenges. A simple screening tool would be beneficial to identify potential patients who have chronic upper respiratory tract disease requiring further specialist evaluation.

Objective: To test a simple screening tool consisting of four questions to detect PCD in children with chronic otitis media and chronic rhinosinusitis seen in a tertiary otolaryngology clinic.

Methods: A prospective, single site, observational study in a tertiary care pediatric otolaryngology clinic. Children aged 3-17 years diagnosed with chronic otitis media or rhinosinusitis with onset at less than 2 years of age were recruited. All study subjects had at least one of four key clinical features for PCD as determined by answers to screening questions, while control subjects had none. All participants completed a medical history questionnaire and nasal nitric oxide measurements. Those with reduced nasal nitric oxide levels were referred to our PCD center for further evaluation.

Results: A total of 153 patients were screened and 62 subjects were enrolled. Of those, 35 were enrolled as study subjects and 27 as matched controls. Study subjects had mean age of 7.5 years (3.2-16.5) with pre-screening diagnosis of chronic otitis media (n = 29) or chronic rhinosinusitis (n = 6). Control subjects (n = 27) had mean age 7.2 years (3.0-16.3) with pre-screening diagnosis of chronic otitis media (n = 25), and chronic rhinosinusitis (n = 2). There were no differences in subject demographics or mean nasal nitric oxide values between the two groups (179.8 vs 210.8 nl/min). Ten individuals had low nasal nitric oxide values, 7 of which were normal on repeat testing. Three subjects failed to return for follow up evaluations. Four referrals were made for further evaluation on the basis of clinical symptoms and nasal nitric oxide results. While no new cases of PCD were detected, a subject and his sibling with recurrent sinopulmonary infections were referred for immunologic evaluation.

Conclusion: The use of standardized screening questions can be used in an otolaryngology clinic to identify patients who require further evaluation for PCD or primary immunodeficiency.

Keywords: Children; Early diagnosis; Nasal nitric oxide; Primary ciliary dyskinesia; Primary immunodeficiency.

Figure 1:

Patient screening and enrollment diagram. The number of subjects meeting each criterion is indicated.

Figure 2:. Nasal nitric oxide levels of subjects.

A: Scatterplot of nasal nitric oxide values versus patient age. The upper limit measure of 77 nL/min used for further evaluation of PCD is denoted by the dashed line. Low initial levels are not shown if retested. B: Repeat testing of low nNO tests (less than 77 nL/min)). Initial and repeated nasal nitric oxide (nNO) levels according to patient study number and corresponding age. Initial and repeat tests for each patient are joined by a line with the arrowhead indicating the repeat test result. Points with no adjoining arrow indicate patients who did not return for follow-up testing.