Effect of Vitamin C on Allergy Skin Test

The Effect of Vitamin C on the Skin Prick Test Wheal Reaction

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

Study Overview

• Status: Recruiting
• Conditions: Allergy; Rhinitis, Allergic
• Intervention / Treatment: Dietary supplement: Ascorbic acid 1000mg; Other: Placebo

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.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Aneeza K W Hamizan, MD; Phone Number: 6046 0391455555; Email: draneeza@ukm.edu.my

Study Locations

• Malaysia
  • WP Kuala Lumpur
    • Cheras, WP Kuala Lumpur, Malaysia, 56000
      • Recruiting
      • Hospital Canselor Tuanku Mukhriz
      • Contact: Aneeza W Hamizan, PhD; Phone Number: 6057 0391455555; Email: draneeza@ukm.edu.my

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Vitamin C; Commercially available Tablet Vitamin C 1000mg per day for 7 days	Dietary supplement: Ascorbic acid 1000mg; Health supplement; Other Names: VItamin C
Placebo Comparator: Placebo; Glucose chewable table 1x per day for seven days	Other: Placebo; Glucose chewable tablet without any ascorbic acid

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skin prick test wheal area of vitamin C group compared to placebo	Skin wheal reaction is measured using computer software. Day 8 wheal area of vitamin C group compared to placebo.	Day 8

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skin prick test wheal reaction at day 8 of intevention compraed to prior skin prick test done as standard of care	Skin wheal reaction are is measured from prior skin test record (baseline) and at day 8 skin test repeated and measured. Area at day 7 - baseline.	Day 8

Collaborators and Investigators

• Sponsor: National University of Malaysia
• Investigators: Principal Investigator: Aneeza K W Hamizan, National University of Malaysia

Publications and helpful links

General Publications

• 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.
• 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.

Study record dates

Study Major Dates

• Study Start (Actual): July 15, 2023
• Primary Completion (Estimated): September 30, 2023
• Study Completion (Estimated): January 30, 2024

Study Registration Dates

• First Submitted: March 30, 2023
• First Submitted That Met QC Criteria: March 30, 2023
• First Posted (Actual): April 12, 2023

Study Record Updates

• Last Update Posted (Actual): August 30, 2023
• Last Update Submitted That Met QC Criteria: August 28, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Keywords: ascorbic acid; skin prick test; vitamin C; antihistamine
• Additional Relevant MeSH Terms: Infections; Respiratory Tract Infections; Respiratory Tract Diseases; Immune System Diseases; Hypersensitivity, Immediate; Otorhinolaryngologic Diseases; Respiratory Hypersensitivity; Nose Diseases; Hypersensitivity; Rhinitis; Rhinitis, Allergic; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Protective Agents; Micronutrients; Vitamins; Antioxidants; Ascorbic Acid
• Other Study ID Numbers: JEP-2023

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Data will be shared if journal is required

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No