荨麻疹和血管神经性水肿（英文）课件

Introduction: Urticaria and Angioedema UrticariaAngioedema Etiology of Urticarial Reactions: Allergic Triggers Acute Urticaria lDrugs lFoods lFood additives lViral infections hepatitis A, B, C Epstein-Barr virus lInsect bites and stings lContactants and inhalants (includes animal dander and latex) Chronic Urticaria lPhysical factors cold heat dermatographi c pressure solar lIdiopathic The Pathogenesis of Chronic Urticaria: Cellular Mediators Histamine as a Mast Cell Mediator Role of Mast Cells in Chronic Urticaria: Lower Threshold for Histamine Release Release threshold decreased by: lCytokines no adverse anticholinergic effects; bid and qd dosing lDisadvantages: Prolongation of QT interval; ventricular tachycardia (astemizole only) in a patient subgroup Four-week Treatment Period: Fexofenadine HCl Mean Pruritus Scores/Mean Number of Wheals/Mean Total Symptom Scores An Approach to the Treatment of Chronic Urticaria Treatment of Urticaria: Pharmacologic Options Antihistamines, others lFirst-generation H1 lSecond-generation H1 lAntihistamine/decongestant combinations lTricyclic antidepressants (eg, doxepin) lCombined H1 and H2 agents Beta-adrenergic agonists lEpinephrine for acute urticaria (rapid but short-lived response) lTerbutaline Corticosteroids lSevere acute urticaria avoid long-term use use alternate-day regimen when possible lAvoid in chronic urticaria (lowest dose plus antihistamines might be necessary) Miscellaneous lPUVA lHydroxychloroquine lThyroxine Atopic Dermatitis: Acute, Subacute, and Chronic Lesions Acute Cutaneous Lesions lErythematous, intensely pruritic papules and vesicles lConfined to areas of predilection cheeks in infants antecubital popliteal Subacute Cutaneous Lesions lErythema excoriation, scaling lBleeding and oozing lesions Chronic Lesions lExcoriations with crusting lThickened lichenified lesions lPostinflammatory hyperpigmentation lNodular prurigo Atopic Dermatitis: Physical Distribution by Age Group Immune Response in Atopic Dermatitis lMarkedly elevated serum IgE levels lPeripheral blood eosinophilia lHighly complex inflammatory responses IgE-dependent immediate hypersensitivity lMultifunctional role of IgE (beyond mediation of specific mast cell or basophil degranulation) lCell types that express IgE on surface monocyte/macrophages Langerhans cells mast cells basophils Atopic Dermatitis: Tests to Identify Specific Triggers lSkin prick testing for specific environmental and/or food allergens lRAST, ELISA, etc, to identify serum IgE directed to specific allergens in patients with extensive cutaneous involvement lTzanck smear for herpes simplex lKOH preparation for dermatophytosis lGrams stain for bacterial infections lCulture for antibiotic sensitivity for staphylococcal infection; supplement with bacterial cultures lCultures to support tests bacterial, viral, or fungal Topical Corticosteroids lRanked from high to low potency in 7 classes Group 1 (most potent): betamethasone dipropionate 0.05% Group 4 (intermediate potency): hydrocortisone valerate 0.2% Group 7 (least potent): hydrocortisone hydrochloride 1% lLocal side effects: Development of striae and atrophy of the skin, perioral dermatitis, rosacea lSystemic effects: Depend on potency, site of application, occlusiveness, percentage of body covered, length of use lMay cause adrenal suppression in infants and small children if used long term Antihistamines and Other Treatments Standard Treatment lOral antihistamines to relieve itching lMoisturizer to minimize dry skin lTopical corticosteroids