Effect of Vitamin C on Allergy Skin Test
The Effect of Vitamin C on the Skin Prick Test Wheal Reaction
This study is testing if taking vitamin C can change the results of allergy skin tests in people who are allergic to house dust mites.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 90 (estimated) |
| Ages | 18 Years to 40 Years |
| Sex | All |
| Sponsor | National University of Malaysia Academic / other |
| Locations | 1 site (Cheras, WP Kuala Lumpur) |
| Trial ID | NCT05810233 on ClinicalTrials.gov |
What this trial studies
This study investigates how vitamin C affects the results of allergy skin tests in individuals with allergic rhinitis. Participants with a history of allergy to house dust mites will be randomly assigned to receive either 1000mg of vitamin C or a placebo for one week. After the intervention, a skin prick test will be conducted to measure the wheal reaction to allergens. The goal is to determine if vitamin C supplementation alters the skin test results, which could impact clinical guidelines for allergy testing.
Who should consider this trial
Good fit: Ideal candidates are adults over 18 with allergic rhinitis and a positive skin prick test to dust mites.
Not a fit: Patients with contraindications to vitamin C or those with certain skin conditions may not benefit from this study.
Why it matters
Potential benefit: If successful, this study could lead to improved accuracy in allergy testing for patients taking vitamin C.
How similar studies have performed: Previous studies have suggested that vitamin C may influence allergy responses, but this specific approach is novel and requires further investigation.
Eligibility criteria
Show full inclusion / exclusion 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)
Where this trial is running
Cheras, WP Kuala Lumpur
- Hospital Canselor Tuanku Mukhriz — Cheras, WP Kuala Lumpur, Malaysia (Recruiting)
Study contacts
- Principal investigator: Aneeza K W Hamizan — National University of Malaysia
- Study coordinator: Aneeza K W Hamizan, MD
- Email: draneeza@ukm.edu.my
- Phone: 0391455555
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.