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Flare Reactions (flare + reaction)

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Medical Sciences100%

Selected Abstracts

Neuronal sensitization for itch in patients with chronic pruritus

EXPERIMENTAL DERMATOLOGY, Issue 9 2004
A. Ikoma
Itch is one of the major symptoms of various skin diseases. Although specific neuronal pathways for itch were identified both peripherally and centrally, they still fail to explain itchy skin observed in patients with chronic pruritus. In this study, sensitivity to itchy and painful stimuli in patients with atopic dermatitis was investigated. Histamine-prick evoked enormous itch in their lesional skin, while less itch in their non-lesional skin than healthy subjects. Flare reaction was not significantly different between their non-lesional and lesional skin, rather smaller than healthy subjects. Mechanical (pin-pricks), electrical, heat and chemical (injection of pH3 solution) stimuli evoked intense itch in their lesional skin and partly also in their non-lesional skin, while only pain in healthy subjects. Itch was also, but not intensely, evoked in healthy subjects by injection of pH3 solution after sufficient histamine stimuli. These results confirm the presence of itchy skin with hyperkinesis (excessive itch by itchy stimuli) and allokinesis (itch by non-itchy stimuli) in patients with atopic dermatitis, which is so intense that painful stimuli cannot suppress but evoke itch, and suggest that neuronal sensitization is involved in their itch not only peripherally but also centrally. [source]

Inhibition of allergen-induced wheal and flare reactions by levocetirizine and desloratadine

BRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 2 2008
Nelly Frossard
What is already known about this subject ,,The reproducible and standardized histamine-induced wheal and flare model helps identify the objective effectiveness of antihistamines in humans, as well as their differences in onset and duration of action. ,,Some of the newest antihistamines have already been compared in a head-to-head setting using this model. However, their objective action at inhibiting the allergen-induced wheal and flare response has not been reported yet. What this study adds ,,The time,response study presented here shows the objective activity of two of the newest generation of antihistamines, levocetirizine and desloratadine, at inhibiting the allergen-induced wheal and flare response in a randomized, cross over, placebo-controlled trial. ,,This model is interesting to the clinical setting since allergic subjects are recruited, and the response to allergen involves mast cell degranulation and release of numerous vasoactive and pro-inflammatory mediators additionally to histamine. ,,In addition, this study reports receptor occupancy for both antihistamines at therapeutic dosage, leading to analysis of potential differences in activity. ,,This study clearly shows the potential anti-inflammatory properties of desloratadine and levocetirizine in their skin activity when allergen is the challenging agent as occurs in the clinical situation. Aims To evaluate the inhibitory activity of the new-generation antihistamines levocetirizine and desloratadine at their therapeutic doses on the allergen-induced wheal and flare reaction at 1.5 h, 4 h, 7 h, 12 h and 24 h postdose, and to measure their plasma and skin concentrations. Methods A double-blind, randomized, cross-over, placebo-controlled study in 18 allergic subjects was carried out. The time,response of the wheal and flare reaction areas under the curve (AUC) were compared by anova. Results Both antihistamines significantly (P < 0.001) inhibited the allergen-induced wheal and flare reactions compared with placebo. Levocetirizine was significantly more potent than desloratadine. Mean ± SEM wheal AUC(0,24 h) was 506.4 ± 81.0 with levocetirizine and 995.5 ± 81.0 mm2 h with desloratadine as compared with placebo (1318.5 ± 361.0 mm2 h). Flare AUC(0,24 h) was 5927.3 ± 1686.5 and 15838.2 ± 1686.5 mm2 h, respectively [P < 0.001 for both compared with placebo (22508.2 ± 7437.1 mm2 h)]. Levocetirizine showed significant inhibition of wheal and flare already at 1.5 h postdose compared with placebo (P , 0.001); desloratadine achieved a significant effect only after 4 h. The mean total plasma concentration at 12 h and 24 h after intake was higher for levocetirizine (58.1 ± 13.4 and 20.0 ± 8.1 ng ml,1, respectively) as compared with desloratadine (0.82 ± 0.24 and 0.45 ± 0.16 ng ml,1). Similarly, higher mean unbound skin concentrations were observed for levocetirizine 24 h after intake (1.80 ng g,1) than for desloratadine (0.07 ng g,1). This was associated with greater receptor occupancy for levocetirizine (54%) than desloratadine (34%) at 24 h. Conclusions Levocetirizine suppressed the cutaneous allergic reactions with a higher potency than desloratadine, which correlated with its high receptor occupancy. Receptor occupancy rather than drug affinity or plasma half-life is more representative of antihistamine potency. [source]

P56 Occupational protein contact dermatitis from shiitake mushrooms

CONTACT DERMATITIS, Issue 3 2004
Renata Kaminska
Case report:, A 54-year-old woman, with no family or personal history of atopy, developed skin symptoms and cough after she had been cultivating shiitake mushrooms for 12 months. The patient reported dermatitis on the backs of her hands, fingers and on her wrists, after 1 or 2 days of being in contact with shiitake mushrooms. The skin lesions and cough disappeared entirely during the holidays. Result: Prick tests to common inhalant allergens, molds and flours were negative, with the exception of D. farinae (3 mm). The prick-to-prick test was positive for shiitake gill (3 mm), shiitake stalk (3 mm) and dry shiitake (8 mm ps). The histamine wheal was 5,7 mm. Control prick tests with shiitake on 5 nonexposed subjects were negative. An open test was performed with shiitake on the flexor side of the upper arm. Within 20 minutes a positive reaction appeared comprising two wheals and flare reactions. Patch test with shiitake gave a strong toxic reaction in 2 days, which continued to diminish on days 3 and 4. Conclusion: Contact urticaria is the clinical skin symptom of immediate allergy, but repeated exposure may lead to protein contact dermatitis. However, our patient has not had urticaria symptoms from shiitake, although the prick-to-prick and open tests were positive. To our knowledge, this is the first report of protein contact dermatitis from shiitake in a patient with a positive immediate skin reaction and negative patch test result. [source]

Tumor flare reactions and response to lenalidomide in patients with refractory classic Hodgkin lymphoma,

AMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2010
Gaetano Corazzelli
First page of article [source]

Inhibition of allergen-induced wheal and flare reactions by levocetirizine and desloratadine

BRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 2 2008
Nelly Frossard
What is already known about this subject ,,The reproducible and standardized histamine-induced wheal and flare model helps identify the objective effectiveness of antihistamines in humans, as well as their differences in onset and duration of action. ,,Some of the newest antihistamines have already been compared in a head-to-head setting using this model. However, their objective action at inhibiting the allergen-induced wheal and flare response has not been reported yet. What this study adds ,,The time,response study presented here shows the objective activity of two of the newest generation of antihistamines, levocetirizine and desloratadine, at inhibiting the allergen-induced wheal and flare response in a randomized, cross over, placebo-controlled trial. ,,This model is interesting to the clinical setting since allergic subjects are recruited, and the response to allergen involves mast cell degranulation and release of numerous vasoactive and pro-inflammatory mediators additionally to histamine. ,,In addition, this study reports receptor occupancy for both antihistamines at therapeutic dosage, leading to analysis of potential differences in activity. ,,This study clearly shows the potential anti-inflammatory properties of desloratadine and levocetirizine in their skin activity when allergen is the challenging agent as occurs in the clinical situation. Aims To evaluate the inhibitory activity of the new-generation antihistamines levocetirizine and desloratadine at their therapeutic doses on the allergen-induced wheal and flare reaction at 1.5 h, 4 h, 7 h, 12 h and 24 h postdose, and to measure their plasma and skin concentrations. Methods A double-blind, randomized, cross-over, placebo-controlled study in 18 allergic subjects was carried out. The time,response of the wheal and flare reaction areas under the curve (AUC) were compared by anova. Results Both antihistamines significantly (P < 0.001) inhibited the allergen-induced wheal and flare reactions compared with placebo. Levocetirizine was significantly more potent than desloratadine. Mean ± SEM wheal AUC(0,24 h) was 506.4 ± 81.0 with levocetirizine and 995.5 ± 81.0 mm2 h with desloratadine as compared with placebo (1318.5 ± 361.0 mm2 h). Flare AUC(0,24 h) was 5927.3 ± 1686.5 and 15838.2 ± 1686.5 mm2 h, respectively [P < 0.001 for both compared with placebo (22508.2 ± 7437.1 mm2 h)]. Levocetirizine showed significant inhibition of wheal and flare already at 1.5 h postdose compared with placebo (P , 0.001); desloratadine achieved a significant effect only after 4 h. The mean total plasma concentration at 12 h and 24 h after intake was higher for levocetirizine (58.1 ± 13.4 and 20.0 ± 8.1 ng ml,1, respectively) as compared with desloratadine (0.82 ± 0.24 and 0.45 ± 0.16 ng ml,1). Similarly, higher mean unbound skin concentrations were observed for levocetirizine 24 h after intake (1.80 ng g,1) than for desloratadine (0.07 ng g,1). This was associated with greater receptor occupancy for levocetirizine (54%) than desloratadine (34%) at 24 h. Conclusions Levocetirizine suppressed the cutaneous allergic reactions with a higher potency than desloratadine, which correlated with its high receptor occupancy. Receptor occupancy rather than drug affinity or plasma half-life is more representative of antihistamine potency. [source]