Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033774 (pruritus)
 14,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of cooling and topical application of menthol on histamine-induced itch, wheal and flare reactions of the left lower arm were investigated in a threefold cross-over design with 15 healthy male volunteers. Lowering skin temperature by cooling from 32.8 +/- 0.3 degrees C to 29.7 +/- 0.5 degrees C reduced itch intensity from 260 +/- 47 units to 55 +/- 12 units (visual analogue scale) and flare diameters from 39.0 +/- 2.0 mm to 30.2 +/- 1.8 mm; wheal reactions were not affected. A similar reduction in itch was found under menthol (42 +/- 14 units) although skin temperature was not decreased. These findings suggest a central inhibitory effect of cold sensitive A-delta fibre activation on itch.
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PMID:Effects of menthol and cold on histamine-induced itch and skin reactions in man. 762 16

This study investigated the effects of single doses of clemastine (2mg orally), mepyramine (2 micrograms intradermally) and placebo on weal and flare caused by intradermal chloroquine 2.5mg and histamine 2 micrograms in 11 healthy black subjects who experienced generalised pruritus with oral chloroquine. Compared with placebo, both antihistamines caused significant reductions in histamine-induced weal and flare. By contrast, chloroquine-induced weal and flare were not significantly altered by clemastine or mepyramine when compared with placebo. It is concluded that histamine is unlikely to be the main mediator of chloroquine-induced weal and flare. These findings are in consonance with the lack of significant effect of antihistamines on chloroquine-induced generalised pruritus.
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PMID:Effects of two antihistamines on chloroquine and histamine induced weal and flare in healthy African volunteers. 762 1

Neurokinins are a family of peptides which are released from sensory nerves. This family involves substance P, neurokinin A and B which stimulate neurokinin-NK1, -NK2 and -NK3 receptors respectively. The neurokinins as well as C.G.R.P. (calcitonin gene related peptide) and V.I.P. (vasoactive intestinal peptide) are the mediators of the non adrenergic non cholinergic (N.A.N.C.) nervous system. All these peptides can be released by nerve fibres innervating the skin. They are mainly inflammatory mediators. At skin level, the neurokinin induce itch, wheal and flare. Itch and flare are partly due to histamine release from mast cells in response to substance P.
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PMID:[Neurokinins and the skin]. 769 70

The new H1-receptor antagonist, cetirizine, is eliminated primarily unchanged by renal excretion and is thus potentially useful for relief of pruritus in patients with hepatic dysfunction, in whom many H1-receptor antagonists are contraindicated. The authors studied the elimination of cetirizine in six patients with primary biliary cirrhosis. In contrast to data obtained in healthy adults with normal hepatic function reported in the medical literature, they found that the mean serum elimination half-life value of cetirizine, 13.8 +/- 1.8 hours, was longer, and the mean clearance rate, 0.44 +/- 0.10 mL/min/kg, was lower (P < .05). The mean peak serum cetirizine concentration, 498 +/- 118 ng/mL, was higher, the mean area under the curve, 6438 +/- 1621 ng/mL/hr, was larger, and the mean fraction of the dose excreted as unchanged cetirizine in the urine, .32 +/- .14, was lower (P < .05). The duration of action of cetirizine was prolonged, as evidenced by significant suppression of the histamine-induced wheal and flare for 48 and 72 hours, respectively, after a single dose. Cetirizine elimination was impaired in patients with hepatic dysfunction.
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PMID:Cetirizine pharmacokinetics and pharmacodynamics in primary biliary cirrhosis. 769 67

Hypersensitivity responses to biting flies such as Culicoides are believed to be the cause of sweet itch, a seasonal intensely pruritic skin condition of horses. Little is known about the mediators released by antigen in the skin of affected horses. In the present study the cutaneous vascular and cellular responses to intradermally injected platelet activating factor (PAF) have been characterised in sweet itch cases during the active phase of the disease and compared with those of Culicoides antigen extract. Histamine was used as a positive control in vascular permeability studies. Responses were also examined in 4 of the 5 sweet itch cases during the inactive phase of the disease. Normal ponies were used as controls. PAF-induced increases in vascular permeability that were dose-related (0.001-1 micrograms per site) and of a similar magnitude in sweet itch and normal animals. Antigen (0.5-50 micrograms per site) also caused dose-related wheal formation in sweet itch cases during the active, but not the inactive, phase of the disease. This effect was biphasic, with maximal responses occurring at 1 and 8 h. An increase in vascular permeability occurred in normal ponies only after administration of the highest dose of antigen tested. Interestingly, histamine (0.02 micrograms per site) induced wheals were significantly smaller in the affected, compared with the normal, group, both during the active and inactive phases. PAF and antigen caused neutrophil accumulation in the skin of sweet itch and normal animals during both the active and inactive phases of the disease. Eosinophil recruitment was also observed but only in the affected group and, in the case of PAF, during the active, but not the inactive, phase. Antigen additionally caused the accumulation of mononuclear cells in the skin of sweet itch cases during the active phase, PAF induced a small increase in mononuclear cell numbers in these animals but the increase was not statistically significant. These findings demonstrate that PAF mimics the effects of Culicoides antigen during the active phase of the disease. Hence, PAF, like histamine, may play a role in the pathogenesis of antigen-induced responses in the skin of sweet itch horses.
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PMID:Platelet activating factor mimics antigen-induced cutaneous inflammatory responses in sweet itch horses. 774 95

In the previous few years, there has been a startling escalation in intraoperative and radiologic anaphylactic episodes, some of them lethal, that have been assigned to rubber exposure. Immediate hypersensitivity reactions to natural rubber pose a significant risk to patient with spina bifida and urogenital abnormalities, health care workers, and rubber industry workers. It has been estimated that 2% to 10% of physicians and nursing personnel are latex allergic. The clinical syndromes associated with reactions to latex may be divided into three broad categories a) contact dermatitis--limited to skin directly in contact with latex, b) contact urticaria syndrome a broad spectrum of contact reactions including not only immediate wheal and flare reactions, but also dyshidrotic vesiculation, and accelerated contact reactions including erythema, burning or pruritus occurring within 10-30 minutes after contact, c) systemic allergic reactions-including generalized urticaria or pruritus, rhinoconjunctivitis or asthma, as well as the multiple presentations of anaphylaxis. Contact dermatitis reactions are thought to be a T-cell mediated type IV reaction, systemic reactions to latex appear to be an IgE-mediated phenomenon. Contact urticaria syndrome seems to be a heterogeneous group of reactions. Diagnosis of latex allergy is made on clinical grounds, however, history alone is insufficient to recognize all patients at risk, and conscientious testing materials are not yet available. Prick tests utilizing extracts from latex gloves or from raw latex preparation can be used but the specificity of this test remains unknown. Skin prick testing must be considered experimental and should be only done by experienced physician. Serologic testing for latex allergy remains a safe alternative, although the sensitivity and specificity of this procedure is still undefined. Prophylactic regimes to avoid rubber exposure and decrease the antigen content of natural rubber products by the rubber industry should be implemented to decrease the rate of sensitization in the future and prevent allergic reactions.
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PMID:[Allergic reaction to products made of natural rubber]. 785 99

The initiation of the antihistamine effect of a single dose of acrivastine (8 mg) or cetirizine (10 mg) on wheals and itch induced by histamine dihydrochloride (10 mg/ml) in the prick test was studied in a randomized cross-over design employing 20 healthy medical students. The prick test was performed before ingestion of the drug and after 15, 20, 25, 30, 60 and 90 min and 2, 3 and 4 h. Local symptoms (itching) were recorded on a visual analogue scale. The inhibitory effect of acrivastine on the histamine wheal was first noticed 20 min (p < 0.01) after ingestion of the drug and that of cetirizine after 60 min (p < 0.001). The maximum effect of cetirizine, at 4 h, was greater than that of acrivastine, at 3 h (p < 0.001). The suppression of itching was first noticed 25 min after ingestion with both drugs.
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PMID:Initiation of the effects of acrivastine and cetirizine on histamine-induced wheals and itch in human skin. 790

The response to the histamine hydrochloride prick skin test was studied in 24 healthy volunteers who received, in random order and at least four days apart, acrivastine (8 mg), terfenadine (120 mg), and placebo. The tests were performed on either side of the back before and at the time of administration (single dose), then every 30 minutes for two hours, and every hour for the following four hours. Evaluation was based on the mean of two measurements of the surface area of the wheal-and-flare reaction accompanied by assessment of topical pruritus. The response to histamine was decreased markedly in the two active treatment groups. Although within one hour of injection, the activity of both antihistamines was consistently greater than that of placebo, the kinetics of action of the two products nevertheless differed; indeed acrivastine was active against flare and wheal earlier (within 30 minutes); terfenadine proved to be more active than acrivastine only on flare and only at the later times (four, five, and six hours). The safety study primarily demonstrated drowsiness in one-fourth of the patients receiving placebo and active treatment.
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PMID:Effects of acrivastine and terfenadine on skin reactivity to histamine. 791 Dec 86

Eighteen adult subjects sensitive to mosquito bites participated in a double-blind, placebo-controlled study with 10 mg cetirizine. The drug was given prophylactically and the subjects were then exposed to bites of Aedes communis mosquitoes in the field. Bite lesions were measured and pruritus was scored with a visual analogue scale at 15 min, 60 min, 12 hr and 24 hr. Cetirizine significantly decreased immediate wealing and pruritus and, interestingly, also had a clear effect on the delayed 12 hr and 24 hr bite papules and pruritus. The diameter of a 15 min mosquito-bite weal was 10.1 +/- 10.4 mm (mean +/- s.d.) with the placebo and 5.9 +/- 5.9 mm with cetirizine treatment (P < 0.05). The 15 min pruritus scores were 36.0 +/- 25.2 and 11.2 +/- 13.2 (P < 0.001), respectively. The diameter of the 24 hr mosquito-bite lesion was 12.6 +/- 21.9 mm with the placebo and 7.4 +/- 16.1 mm with cetirizine treatment (P < 0.01). The 24 hr pruritus scores were 18.9 +/- 25.5 and 6.6 +/- 14.8 (P < 0.01), respectively. These results indicate that, in mosquito-sensitive subjects, prophylactically administered cetirizine is an effective drug against both immediate and delayed mosquito-bite symptoms.
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PMID:Treatment of mosquito bites with cetirizine. 809 95

Nasal polyps are characterized by chronic eosinophilic inflammation and often coexist with rhinitis and asthma. Many patients with polyps have no detectable allergy, and it is considered that allergy, at least in many cases, is not relevant to polyp to pathogenesis. To explore the association of nasal polyps with allergy, 16 patients with polyps and ragweed allergy (PRW +) and 16 patients with polyps who were not allergic to ragweed (PRW-) were compared with patients without polyps, 16 who were allergic to ragweed (NPRW +) and 16 who were not allergic to ragweed (NPRW-), before and during the ragweed season. The level of ragweed allergy was comparable in the PRW+ and NPRW+ populations as determined by ragweed skin test wheal diameter, ragweed IgE RAST percent binding, and total serum IgE. Symptom scores before the ragweed season recorded on visual analog scales for the symptoms of blockage, sneezing, decreased smell, itch, postnatal drip, and runny nose were high in patients in the PRW+ and PRW- groups and did not change during ragweed season. Mean symptom scores were low in the NPRW+ group before ragweed season and increased during the season to levels similar to those of patients in the PRW+ and PRW- groups. Preseason nasal lavage albumin concentration was higher in subjects with polyps than those without polyps (58.5, 98) versus (13.6, 15 micrograms/ml) (p = 0.02) and did not change significantly in any group with seasonal exposure. Data are presented as mean, 1 SD; comparisons are made with unpaired t tests.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Nasal polyps: effects of seasonal allergen exposure. 815 Oct 59


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