Mean Wheal Size Research Articles

The Reproducibility of Skin Prick Tests in Childhood Asthma

Thirty-eight children with chronic perennial asthma were skin prick tested with extracts of 17 common allergens at least once a year for a mean of 7 years. All had multiple responses, the response to house dust extract being positive in 95% of all the skin testing sessions. Over the whole follow-up period, the house dust response was consistently positive in 33 of the 38 children and positive in greater than 85% of sessions in 3 more. Consistent responses were noted to other major allergens though in less children. The mean wheal size reaction of the house dust extract and the mean number of skin prick test positive responses increased with age, reaching their peak near the end of puberty, a period of time when bronchial hyperresponsiveness is known to decrease. This study would support the suggestion that differing populations of mast cells in connective tissue and mucosae might account for the different patterns of response that occur in man.

An investigation of the H 1-receptor antagonist triprolidine: Pharmacokinetics and antihistaminic effects

A single oral dose of triprolidine hydrochloride, 0.04 mg/kg (mean dose 2.7 +/- SD 0.4 mg) was administered to seven healthy, fasting adult volunteers who had never been treated previously with H1-receptor antagonists. Blood sampling and intradermal tests with 0.01 ml of histamine phosphate (0.1 mg/ml) were performed at -0.25, 1, 2, 3, 4, 5, 6, 7, 8, and 12 hours after the dose. Wheal-and-flare circumferences were traced, and the areas were measured by planimetry. Pruritus was quantitated by use of a clinical score. Urine was collected in 6-hour pooled aliquots for a total of 24 hours. Serum and urine triprolidine concentrations were measured by high-performance liquid chromatography. Wheal-and-flare areas and pruritus decreased after the triprolidine dose. Suppression of mean flare size was statistically significant at 2, 3, 6 and 8 hours. Suppression of mean wheal size was not statistically significant at any time compared to predose values. The mean triprolidine serum half-life was 2.1 +/- 0.8 hours. The mean peak serum triprolidine concentration of 15.4 +/- 8.3 ng/ml occurred 2 hours after ingestion. No triprolidine was detected in the serum after 12 hours. The mean urinary excretion of unchanged triprolidine during 24 hours was 1.3 +/- 1.0% of the dose administered.