Allergic Rhinitis
Conditions
Keywords
Allergic, Rhinitis, Pharmacogenetics, Histamine
Brief summary
The hypothesis to be proven is that histamine iontophoresis with measurement of microvascular blood flow by laser Doppler flowmetry can be used as a reliable marker to characterize the normal microvascular cutaneous response to histamine.
Detailed description
The specific aim of this study is to validate iontophoresis (with measurement of microvascular blood flow by laser Doppler flowmetry) in a pediatric cohort as a surrogate marker capable of reliably characterizing the normal physiologic response of the cutaneous microvasculature to histamine. In future studies laser Doppler flowmetry ultimately will be used to assess whether microvascular blood flow determined by a previously validated laser Doppler technique can be used as a reliable surrogate endpoint capable of functionally discriminating the effects of polymorphisms in the genes which are quantitatively important for histamine metabolism. The hypothesis to be proven is that histamine iontophoresis with measurement of microvascular blood flow by laser Doppler flowmetry can be used as a reliable marker to characterize the normal microvascular cutaneous response to histamine.
Interventions
None listed
Sponsors
Children's Mercy Hospital Kansas City
Study design
Observational model
OTHER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
7 Years to 18 Years
Healthy volunteers
No
Inclusion criteria
-Established diagnosis of allergic rhinitis and/or allergic conjunctivitis, and/or allergic asthma either clinically (by presence of rhinitis and/or conjunctivitis with or without associated wheezing) and/or with a positive RAST/skin test to the following allergens: trees, grass, weeds, molds, cat, dog, dust mites and/or cockroach)
Exclusion criteria
* Previous history or laboratory evidence of McCune Albright syndrome, immunodeficiency, mastocytosis, receipt of immunomodulatory treatment, chronic conditions associated with abnormalities of the integument, hepatic or renal compromise, neoplastic disease, movement or neurologic disorders and uncontrolled ADHD * Active atopic dermatitis at the site of the skin prick test or site where histamine iontophoresis will be performed, i.e. active atopic dermatitis on anterior forearms * History of anaphylaxis or anaphylactic like episode * Evidence of pregnancy (by urinary hCG) or lactation * Use of drugs (within a specified time period) of agents capable of altering the response to histamine provocation (e.g., antihistamines, systemic corticosteroids, tricyclic antidepressants) * Presence of any condition that, in the opinion of the investigator, would produce difficulty with adherence to study procedures.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| comparison of histamine iontophoresis laser doppler monitoring with epicutaneous histamine testing in measuring the microvasculature response to histamine | one time point |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| intra-individual variability of histamine iontophoresis with laser doppler monitoring | at least 6 months | Determine the intra-individual variability of histamine iontophoresis with laser doppler flowimetry. Twenty subjects will be asked to return for 2 more visits for histamine iontophoresis with laser doppler flowimetry and the intra-individual variability of the measurement will be determined. |
Countries
United States
Outcome results
None listed