Condition category
Injury, Occupational Diseases, Poisoning
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
Allergen-specific sublingual immunotherapy (SLIT) is an effective disease-modifying treatment for house dust mite-induced allergic rhinitis. However, research on its effectiveness on its concomitant allergic conditions is scarce. As a response, the effectiveness of SLIT in patients with house dust mite (HDM) induced allergic rhinitis, and its concomitant allergic diseases including asthma, allergic conjunctivitis and atopic dermatitis has been evaluated in this study.

Who can participate?
Patients suffering from house dust mite-induced allergic rhinitis.

What does the study involve?
All participants’ records in the standardized questionnaire reflecting their progress including their symptoms, medication use and side effect were retrieved and reviewed. Participants were allocated to one of the two groups depending on whether they received sublingual immunotherapy in allergy centre. Participants in the study group received sublingual immunotherapy with house dust mite allergen extract daily for at least 12 months in addition to conventional treatment. Participants in the control group received conventional treatment as usual practice. Symptom scores of allergic rhinitis, asthma, allergic conjunctivitis, and eczema were assessed. The medication usage including antihistamines and nasal topical steroids were also recorded. Any treatment-related side effect during the study period was documented according to the grading system recommended by the World Allergy Organization.

What are the possible benefits and risks of participating?
Participants need to complete a standardized questionnaire each time during their follow up visits for up to 36 months during the study period. Otherwise, there is no additional risk by taking part in this study. All Participants’ record data were anonymized.

Where is the study run from?
Allergy Centre of Hong Kong Sanatorium & Hospital

When is the study starting and how long is it expected to run for?
1 March 2019 to 1 March 2021

Who is funding the study?
Allergy Centre of Hong Kong Sanatorium & Hospital

Who is the main contact?
Dr. Alson Chan

Trial website


Contact information



Primary contact

Dr Alson Chan


Contact details

Allergy Centre
Hong Kong Sanatorium & Hospital
Li Shu Pui Block
2 Village Road
Happy Valley
Hong Kong
Hong Kong

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number

HKSH RC-2019-06

Study information

Scientific title

Effectiveness of allergen-specific sublingual immunotherapy for house dust mite-induced allergic rhinitis and its co-morbid conditions



Study hypothesis

Allergen-specific sublingual immunotherapy is an effective treatment for house dust mite-induced allergic rhinitis, as well as it co-morbid allergic conditions

Ethics approval

Approved 25/02/2019, Hong Kong Sanatorium & Hospital Research Ethics Committee (Research Ethics Committee, Hong Kong Sanatorium & Hospital, 38/F, Li Shu Pui Block, 2 Village Road, Happy Valley, Hong Kong; +852 2572 0211;, ref: RC-2019-06.

Study design

Retrospective Case Control Study

Primary study design


Secondary study design

Case-control study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet.


House dust mite induced allergic diseases


Patients diagnosed to have house dust mite-induced perennial allergic rhinitis according to ARIA guidelines who received sublingual immunotherapy (SLIT) with sublingual allergen extract for over 12 months were enrolled as case, and controls were age- and sex-matched patients with the same diagnosis who were never treated with SLIT. All enrolled patients will be followed up regularly once every 3 months and given a standardized questionnaire at every visit to record their symptom severity, medication use and treatment-related adverse events. They will be followed-up regularly until 36 months.

Intervention type



Not Applicable

Drug names

House dust mite sublingual allergen extract

Primary outcome measure

Symptom scores are measured using a standardized questionnaire at baseline and then every 3 months.

Secondary outcome measures

Medication use is measured using a standardized questionnaire at baseline and then every 3 months.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Suffering from house dust mite-induced perennial allergic rhinitis.

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Incomplete records of clinical data.
2. Concurrent systemic immunological disorders.
3. Using immunomodulatory treatment.

Recruitment start date


Recruitment end date



Countries of recruitment

Hong Kong

Trial participating centre

Hong Kong Sanatorium & Hospital
2 Village Road, Happy Valley, Hong Kong
Hong Kong
Hong Kong

Sponsor information


Hong Kong Sanatorium & Hospital

Sponsor details

2 Village Road
Happy Valley
Hong Kong
Hong Kong
+852 2572 0211

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Hong Kong Sanatorium & Hospital

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Study results on primary, secondary and relevant outcomes will be published in a peer reviewed medical journal.

IPD sharing statement: the datasets generated and/or analysed during the current study during this study will be included in the subsequent results publication.

Intention to publish date


Participant level data


Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

14/05/2019: Trial's existence confirmed by the Hong Kong Sanatorium & Hospital Research Ethics Committee.