Effect of Vitamin C on Allergy Skin Test

NCT ID: NCT05810233

Last Updated: 2023-08-30

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 90 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-07-15
• Study Completion Date: 2024-01-30

Brief Summary

This study will assess the effect of taking vitamin C on allergy skin test.

Detailed Description

Allergic rhinitis (AR) is an Immunoglobulin E (IgE) mediated inflammation of the nasal cavity. House dust mite is the most common causative allergen. The skin prick test is the preferred method to confirm allergy. This test is interpreted by measuring the skin wheal reaction in response to allergen application and histamine. Prior studies have shown that Vitamin C may have antihistamine effect that may reduce the wheal reaction in skin prick test thus cause difficulties to interpret the results. Current guidelines do not recommend cessation of vitamin C prior to skin prick test. This will require further study in order to further understand the effect of vitamin C in commercially available dose on the skin prick test wheal reaction. In this randomized placebo controlled trial, consecutive participant visiting the ENT clinic with allergic rhinitis and prior positive skin prick test towards dust mite will be screened for inclusion and exclusion criteria. Participants will either receive vitamin C 1000mg daily for 7 days or placebo. The skin prick test will be performed after one week of intervention and the area of the wheal reaction area (mm2) and longest diameter (mm) recorded. This will be compared between the two groups. The expected outcome is that participants with oral supplementation of vitamin C will have reduced SPT wheal reaction compared to placebo group.

Conditions

Rhinitis, Allergic; Allergy

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: QUADRUPLE

Study Groups

Vitamin C

Commercially available Tablet Vitamin C 1000mg per day for 7 days

Group Type: EXPERIMENTAL

Ascorbic acid 1000mg

Intervention Type: DIETARY_SUPPLEMENT

Health supplement

Placebo

Glucose chewable table 1x per day for seven days

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: OTHER

Glucose chewable tablet without any ascorbic acid

Interventions

Ascorbic acid 1000mg

Health supplement

Intervention Type: DIETARY_SUPPLEMENT

Placebo

Glucose chewable tablet without any ascorbic acid

Intervention Type: OTHER

Other Intervention Names

VItamin C

Eligibility Criteria

Inclusion Criteria

• Participants above 18-years old
• Participants with history at least 2 symptoms of rhinitis triggered by dust
• Positive SPT to Dermatophagoides pteronyssinus with wheal reaction of at least 5 mm done within the past 1 year.

Exclusion Criteria

• Prior skin prick test result form do not include a tracing of the wheal reaction.
• Prior skin prick test was not performed in HCTM.
• Participants who are actively smoking or who have smoked cigarette or vaped in the past 6 months
• Participants with skin conditions affecting the volar aspects of the arm.
• Participants on beta-blockers
• Participants contraindicated for skin prick test (pregnancy, history of anaphylaxis, poorly controlled asthma)
• Participants on long term supplements (multivitamin, traditional supplement)
• Participants contraindicated for vitamin c (vitamin c allergy, kidney dysfunction, history of kidney or bladder stones, hyperuricemia, thalassemia, G6PD deficiency, sickle cell disease, hamatochromatosis)
• Participants at risk of vitamin C deficiency (hyperthyroidism, elderly, beastfeeding, diarrhoea, restricted diet secondary to inflammatory bowel disease, anorexia or cancer)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National University of Malaysia

OTHER

Sponsor Role: lead

Responsible Party

ANEEZA KHAIRIYAH WAN HAMIZAN

Associate Professor, Dr

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Aneeza K W Hamizan

Role: PRINCIPAL_INVESTIGATOR

National University of Malaysia

Locations

Hospital Canselor Tuanku Mukhriz

Cheras, WP Kuala Lumpur, Malaysia

Site Status: RECRUITING

Countries

Malaysia

Central Contacts

Aneeza K W Hamizan, MD

Role: CONTACT

draneeza@ukm.edu.my

0391455555 ext. 6046

Facility Contacts

Aneeza W Hamizan, PhD

Role: primary

draneeza@ukm.edu.my

0391455555 ext. 6057

References

Skoner DP. Allergic rhinitis: definition, epidemiology, pathophysiology, detection, and diagnosis. J Allergy Clin Immunol. 2001 Jul;108(1 Suppl):S2-8. doi: 10.1067/mai.2001.115569.

Reference Type: BACKGROUND

PMID: 11449200 (View on PubMed)

Fortner BR Jr, Danziger RE, Rabinowitz PS, Nelson HS. The effect of ascorbic acid on cutaneous and nasal response to histamine and allergen. J Allergy Clin Immunol. 1982 Jun;69(6):484-8. doi: 10.1016/0091-6749(82)90171-3.

Reference Type: BACKGROUND

PMID: 7076989 (View on PubMed)

Other Identifiers

JEP-2023

Identifier Type: -

Identifier Source: org_study_id