1. URTICARIA:A chalenging disorder to physicians Prof . M.YOUSRY ABDEL-MAWLA.

42. Not yet demonstrated in skin H 3 Negative feedback inhibition of histamine synthesis and release Not H 1 or H 2 Probably requires dose level in excess of the licensed dosage Unknown Antiallergic Involves blockade of central and peripheral muscarinic receptors; second-generation antihistamines have little or no effect on muscarinic receptors Muscarinic Anticholinergic Antagonises "arousal" action of histamine in CNS; depends on lipophilicity of the antihistamine H 1 Sedative (mainly first generation) Competitive antagonist at H 1 (and H 2 ) receptors H 1 H 2 Anti-inflammatory Comment Receptor Action TABLE-- PHARMACOLOGIC ACTIONS OF H 1 ANTIHISTAMINES

43. As for promethazine 10-20 Trimeprazine Powerful sedative action, rapid action, useful in acute urticaria, angioedema 25-50 Promethazine 25-50 Phenindamine 5 Mequitazine 25-50 Diphenhydramine 1-2 Clemastine Sedative, no special features 1-2 Azatadine As for chlorpheniramine 4-8 Brompheniramine Sedative, rapid action, useful in acute urticarias and angioedema 4-8 Chlorpheniramine Strongly sedative anxiolytic, useful to allay itching as nighttime treatment in urticaria, eczema 25-50 Hydroxyzine Special Features Adult Single Dose (mg) First Generation TABLE-- ANTIHISTAMINES CURRENTLY LICENSED

44. 180 Adult single dose for allergic rhinitis is 120 mg. Tricyclic antidepressant with potent H 1 and H 2 antihistamine activity, powerfully sedative and anxiolytic 10-50 Doxepin Sedative, claimed to have mast cell-stabilizing activity 1-2 Ketotifen Miscellaneous Nonsedative Fexofenadine Third Generation Low sedation 10 Mizolastine Low sedation 10 Loratadine Low sedation, claimed to possess additional antiallergic action 10 Cetirizine Low sedation 8 Acrivastine Second Generation Sedative antihistamine with additional antiserotonin activity 4-8 Cyproheptadine

48. UVA = ultraviolet A light; UVB = ultraviolet B light. Topical and systemic corticosteroids; oral antihistamines; treatment of the underlying cause Annular patches with trailing scale inside erythematous borders Erythema annulare centrifugum Topical, intralesional and systemic corticosteroids; antimalarials Annular or papulosquamous plaques, with or without scale, on sun-exposed areas Subacute cutaneous lupus erythematosus Oral antihistamines Evanescent annular, nonscaly, erythematous plaques Urticaria Dapsone; rifampin (Rifadin) Erythematous annular plaques, with or without scale Hansen's disease Topical, intralesional and systemic corticosteroids; antimalarials; thalidomide Indurated, erythematous plaques Sarcoidosis Topical and intralesional corticosteroids Indurated, nonscaly, skin-colored annular plaques and papules, usually on the extremities Granuloma annulare Topical and systemic corticosteroids; UVA, UVB Small, fawn-colored, oval patches with fine scale along the borders, following skin cleavage lines Pityriasis rosea Topical and systemic antifungals Scaly, annular, erythematous plaques or papules on glabrous skin Tinea corporis Treatment options Clinical presentation Diagnosis TABLE -- Comparison of Annular Lesions including urticaria

55. Thank you Thank you