ABSTRACT
In order to investigate the effect of cis-urocanic acid (UCA) on a delayed-type hypersensitivity response in humans, a contact hypersensitivity reaction was induced on four test sites on the back of 33 volunteer subjects. The first test site was pretreated with cis-UCA immediately before application of the allergen. The second and third test sites were posttreated on the second and third days of the hypersensitivity response with cis-UCA and a class III corticosteroid, respectively. The fourth test site was used as a positive control. The cutaneous blood flow of the test sites was measured using laser Doppler flowmetry. Pretreatment with cis-UCA reduced the hypersensitivity response significantly. It is possible that cis-UCA could be used in the preventive treatment of contact hypersensitivity responses.
Subject(s)
Dermatitis, Contact/drug therapy , Urocanic Acid/therapeutic use , Adolescent , Adult , Aged , Anti-Inflammatory Agents/therapeutic use , Betamethasone Valerate/therapeutic use , Blood Flow Velocity , Dermatitis, Contact/physiopathology , Female , Humans , Laser-Doppler Flowmetry , Male , Middle AgedABSTRACT
To establish the existence of intra-regional variations in response to allergens on the back, we performed patch tests in 21 patients at 2 different sites on the back. Visual readings using the numerical scale established by the International Contact Dermatitis Research Group were carried out 2 days after application of the allergen. After each visual reading, the skin blood flow at the test sites was quantified by laser Doppler flowmetry. The results of laser Doppler flowmetry showed a highly significant difference between the upper and lower back. It is therefore necessary that in quantitative and comparative investigations, symmetrical sites, i.e., left versus right sides of the body, should be studied.
