THIS CHAPTER reviews the common and uncommon immunologically mediated diseases of the skin. Newer information concerning the pathogenesis of these diseases, reviewed herein, promises to improve the diagnosis and treatment of these conditions.
URTICARIA AND ANGIOEDEMA
Urticaria consists of blanchable, erythematous, edematous papules and plaques, usually pruritic, ranging from 1 to 2 mm to several centimeters in diameter, often with serpiginous borders. Individual lesions are transient, infrequently persisting. longer than 24 to 48 hours. Characterized by well-demarcated swelling of deeper skin structures and subcutis (with a predilection for palms, soles, and periorbital-perioral areas), angioedema may present as nonpitting edema. The overlying skin appears normal and is nonpruritic; a burning discomfort may occur.
Urticaria and angioedema are common.1,2 The incidence in the general population is approximately 15%. Women are more frequently afflicted, and onset may occur at any age, with peak incidence in the second through fourth decades of
Horan RF, Schneider LC, Sheffer AL. Allergic Skin Disorders and Mastocytosis. JAMA. 1992;268(20):2858-2868. doi:10.1001/jama.1992.03490200110012