The Journal of allergy and clinical immunology
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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.