Clinical trial NCT01172613: Optimal Concentration of Dermatophagoides Pteronyssinus (Dp) Allergen Extract for Skin Prick Test (SPT) of Thai Population
Official title: Optimal Concentration of Allergen Extract of Dermatophagoides Pteronyssinus to be Used in Diagnostic Allergy Skin Prick Test Among Thai Population
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Rhinitis, Allergic, Perennial
Rhinitis, Allergic, Seasonal
Skin Prick Test
Keywords: allergic rhinitis
concentration of diagnostic reagent
allergen extract, house dust mites (Dp)
skin prick test
nasal allergen provocation test
Lead sponsor: Siriraj Hospital
Sponsor class: OTHER
First posted: 2010-07-30
Enrollment: 110
Sex: ALL
Minimum age (years): 15
Maximum age (years): 60
Standard ages: CHILD
ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: allergic rhinitis patients in Siriraj hospital (tertiary care) control group: healthy subjects from community sample

Brief summary: The purpose of this study is to determine the appropriate concentration of diagnostic reagent of house dust mite (Dp) to be used in diagnostic allergy skin prick test among Thai population with allergic rhinitis.

Detailed description: The current allergy diagnostic reagent of house dust mites marketed in the USA is at 10,000 AU/ml. This is based on the IDEAL50 concept put forth by Turkeltaub et al, almost 3 decades ago. Such concentration has been shown to give large degree of false positives even in the US population.

In Thailand, it was anecdotally observed that at such concentration, sizes of positive tests among atopic subjects were quite large and could lead to discomfort and a possible anaphylaxis in certain allergic individuals. Moreover, up to 40% of normal individuals could give positive reaction to this concentration.

It is therefore desirable to reexamine the appropriate concentration of diagnostic reagent of house dust mites among the Thai population and will be the main objective of this research.

Eligibility criteria: Inclusion Criteria:allergic rhinitis

* clinical diagnosis of allergic rhinitis
* has skin prick test positive to standard Dp extract (wheal diameter 3 mm. or greater)
* not take any medications that interfere the tests (skin prick test and nasal allergen provocation test)

Inclusion Criteria:healthy subject

* no underlying disease
* not take any medications that interfere the tests (skin prick test and nasal allergen provocation test)

Exclusion Criteria:

* has skin prick test positive to standard Dp extract with wheal diameter more than 10 mm.
* has chronic disease eg. HIV infection, neurological diseases, hypertension, cardiac diseases, pulmonary diseases, hepatobiliary diseases, renal diseases, endocrinological diseases, congenital malformation, malignancy
* if has asthma, uncontrolled asthma symptom or PEF \< 70%
* during pregnancy or lactation
* has chronic skin disease
* participate other project within 30 days
* has abnormal anatomy of the nose

Primary outcomes:
measure: appropriate concentration of diagnostic reagent of house dust mite (Dp)
timeFrame: 15 minutes
Secondary outcomes:
measure: false positive rates of various dilutions of diagnostic reagent (house dust mite: Dp) that be used in skin prick test in Thai healthy population
timeFrame: 15 minutes
measure: false negative rates of various dilutions of diagnostic reagent (house dust mite: Dp) that be used for diagnosis allergic rhinitis in Thai population by skin prick test
timeFrame: 15 minutes
Other outcomes:
Locations:
city: Bangkok
country: Thailand
facility: Siriraj Hospital
city: Bangkok
country: Thailand
facility: Siriraj Hospital
Study officials:
affiliation: Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University
name: Professor Pakit Vichyanond, MD
role: PRINCIPAL_INVESTIGATOR
References: