Study on Association Between Treatment of Allergic Rhinitis and Cognitive Ability in Children

Pilot study on the association between allergic rhinitis and cognitive ability in 174 children aged 11-14 within the same year group at school in which 140 Allergic Rhinitis subjects and 34 non-Allergic Rhinitis subjects. Primary outcome measures include cognitive tests (Trait Making Test, Digit Span Test, Stroop Test, Chinese Auditory Verbal Learning Test, Verbal Fluency Test), so as to assess the cognitive ability of allergic rhinitis patients before and after treatment compared to a control group. Rhinitis Symptom Utility Index (RSUI) of patients will be the secondary outcome measured through questionnaires. Positive skin prick test and endoscopy examination (taking place in Prince of Wales hospital) will be required before the diagnosis of allergic rhinitis. The data will be analysed by the Multilevel models.

INTRODUCTION Allergic rhinitis is the reportedly second most common reported chronic health condition in Hong Kong children under the age of 14, with the Child Health Survey 2005-2006 indicating a prevalence of 24.5%. Allergic rhinitis is a type I hypersensitivity reaction, which occurs when IgE antibodies are produced against allergens, leading to the activation of mast cells which release inflammatory mediators. Common allergens in Hong Kong include house dust mite and cockroaches. Allergic rhinitis causes a multitude of symptoms including itching, sneezing, nasal discharge, post-nasal drip, and nasal congestion. It can cause poor quality sleep, leading to daytime sleepiness, decreased cognitive ability, mood instability and fatigue. Allergic rhinitis leading to a reduction in quality of life in adults has been well established, leading to impediment of cognitive processes and poorer ability in attention-requiring activities (e.g. driving). These symptoms can similarly significantly impede a child's education and quality of life. It is estimated that up to 90% of allergic rhinitis patients are untreated, insufficiently treated, or inappropriately treated.

With regards to children and teenagers, some studies have suggested that allergic rhinitis can cause significant cognitive difficulties, with detrimental effects on children's education and examination performance, however others suggest there is no association. A longitudinal cohort study in 2014 on the treatment of allergic rhinitis in children showed an improvement in attention and divided attention after 1 year of treatment. There are little studies regarding the effect of treatment of allergic rhinitis on cognitive abilities in children.

RESEARCH OBJECTIVES

1. To investigate, if any, the differences between normal and allergic rhinitis patients in terms of cognitive function
2. To investigate the impact of allergic rhinitis on different areas of cognitive function
3. To investigate the improvement of cognitive function in children after 8 weeks of standard treatment of allergic rhinitis

RESEARCH HYPOTHESIS Children with allergic rhinitis are expected to have a heightened improvement in cognitive abilities after the treatment compared to the normal control group due to relief of their nasal symptoms.

STUDY DESIGN This study is a prospective longitudinal pilot study to take place from 15 1 Nov Dec 2017 to 31 Dec 2018. Final report will be completed 30 June 2019.

STUDY SAMPLE AND SETTING The study is to be performed in Hong Kong, with subjects aged 11-14 studying Form 1 and 2 in secondary school being recruited. Recruitment and cognitive testing will take place at the secondary school, whilst physician follow up and skin prick tests will take place at Prince of Wales Hospital. Healthy individuals as well as patients with a history of allergic rhinitis will be recruited. Chinese will be the main language used. The total number of the Form 1 students within the school will be around 200. The estimated participation rate will be approximately 70%. As the prevalence of allergic rhinitis in Hong Kong children under the age of 14 is approximately 24.5%, the expected number of Allergic Rhinitis participants and non-Allergic Rhinitis participants are 140 and 34 respectively.

Eligibility Criteria:
Inclusion Criteria:

- Control Group- Inclusion Criteria

1. Both genders of 11-14 years
2. Chinese in ethnicity
3. Subjects who have not been diagnosed with a long term medical or psychiatric problem
4. Subjects who are not currently undergoing any long term medical treatment.

Patient Group- Inclusion Criteria

1. Both genders of 11-14 years, diagnosed with allergic rhinitis on basis of screening instruments, medical history, clinical assessment (by general ORL examination including nasal endoscopy)
2. Chinese in ethnicity
3. Positive skin prick test with wheal diameter \>= 3mm
4. Ability to understand the nature, scope, and possible consequences of the study
5. Capability and willingness to comply with the requirements of the protocol

Exclusion Criteria:

1. Subjects with co-existing nasal conditions other than AR, which may affect nasal pathology (nasal polyposis, sinusitis, severe deviations of nasal septum, tumours of the nasal cavity, acute/chronic rhinosinusitis or any underlying pathology that might affect nasal breathing or nocturnal sleep)
2. Subjects with prior nasal surgery (e.g. nasal cavity, sinuses)
3. Subjects with known brain disorders, prior brain surgery or history of stroke
4. Subjects diagnosed with learning disability, autism or attention deficit hyperactivity disorder (ADHD)
5. Subjects with history of known sleep disorder, central or obstructive sleep apnea, narcolepsy, insomnia, patients requiring regular sleep medication and those hypersensitive to applied topical nasal steroids
6. Subjects who have taken topical nasal steroids, oral anti-histamines or medications affecting nasal symptoms 30 days prior to commencement of study
7. Subjects with hypersensitivity reactions towards topical nasal steroids or oral anti-histamines
8. Subjects previously diagnosed with any psychiatric disorders
9. Subjects who suffered from a respiratory tract infection within the past 30 days
10. Subjects who have clinically major cardiovascular, respiratory, hepatic, neurological, endocrine, immunological or other major systemic disease(s)
11. Subjects who are undergoing a long-term medical treatment plan