Study identifies four classes of childhood allergic rhinitis

Researchers used latent class analysis to identify four subgroups of children with allergic rhinitis based on patterns of clinical symptoms and comorbidities, according to a study published in Pediatric Allergy and Immunology.

Classification of allergic rhinitis (AR) — which is common in childhood and can have a major adverse impact on quality of life — traditionally has been based on seasonal and perennial symptom patterns.

S. Tolga Yavuz, MD, of the department of pediatric allergy at University of Bonn Children’s Hospital, and colleagues hypothesized that there are different AR patterns in childhood and that identification of these patterns may help clinicians determine whether they are linked to distinct mechanisms. Thus, researchers aimed to identify distinct phenotypes among children with AR using data-driven techniques.

The study included 510 children aged 5 years to 17 years (male, n = 352; mean age, 10.5 ± 3.5 years) diagnosed with AR by a pediatric allergist between 2011 and 2017 at the Gulhane Military School of Medicine Pediatric Allergy and Asthma Unit.

The pediatric allergy specialist diagnosed AR based on current upper respiratory symptoms such as nasal blockage, rhinorrhea, and nasal itching and sneezing after allergen exposure and on at least one positive skin prick test (SPT) to common inhalant allergens.

Researchers classified AR as moderate/severe among patients experiencing one or more indicators, including sleep disturbances; presence of troublesome symptoms; and impaired daily activities, leisure/sport, school or work. Patients who did not experience any of these indicators were diagnosed with mild AR.

Interviewer-administered questionnaires assessed symptoms, medication use and diagnoses of allergic diseases and environmental exposures, in addition to other data collected to define AR severity and medical history.

All the children received SPTs for aeroallergens common to the region, as well as pulmonary function tests. Researchers also determined blood eosinophil counts.

According to the study, 117 (22.9%) children had mild intermittent AR, 92 (18%) had mild persistent AR, 63 (12.4%) had moderate-severe intermittent AR, and 238 (46.7%) had moderate-severe persistent AR. Also, 205 (40%) of the children had asthma.

The researchers then conducted a latent class analysis using 17 variables: allergic conjunctivitis, eczema, asthma, maternal and paternal history of asthma, maternal and paternal history of allergic rhinitis, skin sensitization to eight common allergens, tonsillectomy and adenoidectomy. They used the results to categorize the children into latent classes based on AR with grass monosensitization and conjunctivitis (class 1: n = 361; 70.8%), AR with house dust mite sensitization and asthma (class 2: n = 75; 14.7%), AR with pet and grass polysensitization and conjunctivitis (class 3: n = 35, 6.9%), and AR among children with tonsils and adenoids removed (class 4: n = 39; 7.6%).

There were significant differences in the duration, severity and temporal patterns of AR and allergic conjunctivitis between the four latent classes, the researchers said.

For example, boys were more likely to be in class 3 (OR = 2.51; 95% CI, 1.08-5.8). Also, perennial AR was markedly and significantly more common among children in class 2 (OR = 5.83; 95% CI, 3.42-9.94) and class 3 (OR = 2.88; 95% CI, 1.36-6.13).

Additionally, children in class 3 more commonly experienced mild and intermittent AR symptoms than children in class 1, and children in class 1 more commonly had a maternal history of AR than children in the other classes.

Finally, the children in class 1 experienced more severe AR than the other three classes, which the researchers said indicated that children with isolated seasonal rhinitis have more severe upper respiratory symptoms than children with rhinitis and coexisting asthma.

The researchers acknowledged the potential of bias in their study due to their use of parental reporting. The study also lacked longitudinal investigation, and its results may not be generalizable to other contexts, they added.

“Our findings may have potentially important clinical implications,” the researchers wrote. “Given that asthma is more strongly associated with specific phenotypes of rhinitis, our results emphasize the importance of careful assessment of asthma symptoms and lung function among children with rhinitis who are sensitized to house dust mites and molds. Furthermore, as severe and persistent symptoms should be expected in children with grass pollen monosensitization, physicians may consider early initiation of allergen immunotherapy in such children.”