The Journal of allergy and clinical immunology
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J. Allergy Clin. Immunol. · Dec 1990
Randomized Controlled Trial Comparative Study Clinical Trial Controlled Clinical TrialUrticaria: clinical efficacy of cetirizine in comparison with hydroxyzine and placebo.
Chronic urticaria is a problem for both physician and patient. In an effort to avoid the risks associated with corticosteroid treatment, many first-generation H1-receptor antagonists have been tried and found to induce undesirable levels of sedation when given in amounts sufficient to control urticaria. Cetirizine, a pharmacologically active oxidized metabolite of hydroxyzine, was developed to provide selective H1-receptor inhibition without depression of the central nervous system. ⋯ The incidence of somnolence in the cetirizine group was not significantly different from that of the placebo group. However, in the hydroxyzine group, the incidence of somnolence was significantly higher than that in the placebo group (p = 0.001). The results of this study demonstrate that cetirizine has a greater safety margin over the older parent drug hydroxyzine.
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J. Allergy Clin. Immunol. · Oct 1990
ReviewThe use of antihistamines in the prevention and treatment of anaphylaxis and anaphylactoid reactions.
The pathophysiologic effects of histamine in anaphylaxis have been shown to be mediated through H1 and H2 receptors, individually and in combination. H1 receptors mediate coronary artery vasoconstriction, wheezing, cutaneous vascular permeability, and possibly an increase in pulse rate. H2 receptors stimulate ventricular and atrial inotropy, arterial chronotropy, coronary vasodilation, and rises in basophil cyclic adenosine 3':5' monophosphate (cyclic AMP). (Neither receptor mediates increases in cyclic AMP in mast cells.) H1 and H2 receptors in combination seem to be most potent in mediating flush, headache, increases in pulse pressure, and decreases in diastolic blood pressure. ⋯ Concurrently, retrospective observations of the prevention of anaphylactic reactions to chymopapain have been recorded. Despite some conflicting and inconclusive data, the sum of these studies indicates that pretreatment with a combination of H1 and H2 antagonists is more effective than H1 antagonists alone in preventing reactions to these agents. These results, when added to the available knowledge of the physiology of histamine release, support the preferential use of H1/H2 antagonist combinations in the prevention and treatment of anaphylaxis and anaphylactoid reactions.
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J. Allergy Clin. Immunol. · Oct 1990
Acute hemorrhagic edema of infancy (AHEI)--a variant of Henoch-Schönlein purpura or a distinct clinical entity?
Acute hemorrhagic edema of infancy (AHEI) is an acute cutaneous leukocytoclastic vasculitis (LCV) of infants. The clinical picture has a violent onset with a short benign course followed by spontaneous complete recovery. We report 12 infants with AHEI who were studied clinically, serologically, and immunohistologically. ⋯ Although histopathologic findings are similar, the immunohistologic pattern found in our series of AHEI is rather different from the pattern of HSP. Taking all of these findings into account, we suggest that AHEI should be considered as a separate, clinicopathologic entity or a possible variant of HSP. The more descriptive term "acute benign cutaneous LCV of infancy" is offered for this clinicopathologic entity.
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J. Allergy Clin. Immunol. · Sep 1990
Randomized Controlled Trial Clinical TrialRepeated exposure of asthmatic airways to inhaled adenosine 5'-monophosphate attenuates bronchoconstriction provoked by exercise.
Inhaled adenosine 5'-monophosphate (AMP) induces bronchoconstriction in subjects with asthma, probably caused by histamine release from airway mast cells, and repeated AMP bronchial challenge leads to attenuation of the bronchoconstrictor response. Since exercise-induced bronchoconstriction may be mediated by hypertonic mast cell degranulation, we postulated that repeated AMP bronchial challenge should reduce the response to subsequent exercise challenge. Eight atopic subjects with asthma took part in an unblinded, randomized trial. ⋯ On the AMP study day, the geometric mean PC20 was 15.3 (7.9 to 29.5) mg/ml for the first test, and 28.2 (10.7 to 77.4) mg/ml for the third test (not significant). On the control study day, the mean maximum percentage fall in FEV1 after exercise was 28.0% +/- 2.7%, whereas on the AMP study day, it was reduced to 13.0% +/- 4.3% (p less than 0.01). A significant correlation was found between the change in responsiveness to AMP induced by repeated challenge and the attenuation of the subsequent exercise response (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Allergy Clin. Immunol. · Sep 1990
Enhanced reactive oxygen species metabolism of airspace cells and airway inflammation follow antigen challenge in human asthma.
Airflow limitation and airway inflammation follow antigen bronchoprovocation in sensitized individuals. Inflammation likely results from the interplay of several previously demonstrated factors, but the participation and persistence of enhanced reactive oxygen species (ROS) metabolism of airspace cells after antigen challenge have received more limited attention. We studied nine subjects with mild asthma by bronchoalveolar lavage before and 48 (one subject) to 72 (eight subjects) hours after antigen bronchoprovocation and compared airspace cell numbers and types, cell function, and bronchoalveolar lavage fluid protein, albumin, and immunoglobulins. ⋯ Eosinophil influx was a notable component of the increased airspace cells in postchallenge lavages. Airspace cells demonstrated significantly enhanced ROS metabolism, and total protein, albumin, and IgM levels were higher in postchallenge lavage specimens. Antigen bronchial challenge produces airspace inflammation, which may develop, in part, as a consequence of enhanced ROS metabolism of airspace cells.