ABSTRACT
I. Introduction 233
II. Classification and Definitions 237
III. Contact Urticaria and Exogenous Dermatitis 238
A. Contact Urticaria leading to Secondary Hand Dermatitis (CU′ 2° HE)
B. Concomitant Contact Urticaria and Allergic Contact Dermatitis (CU-ACD)
C. Concomitant Contact Urticaria and Irritant Contact Dermatitis (CUICD)
D. Protein Contact Dermatitis (PCD) 239 E. Latex Glove Contact Urticaria (LGCU) 240
IV. Contact Urticaria and Exogenous Dermatitis 241
A. Concomitant Contact Urticaria and Atopic Dermatitis 241
V. Clinical Features 241
VI. Diagnostic Methods 242
VII. Conclusion 243
References 243
I. INTRODUCTION
Contact urticaria syndrome (CUS), first defined as a biologic entity in 1975,1 comprises a heterogeneous group of transient inflammatory reactions appearing within minutes to hours after contact with the eliciting substance. This reaction may occur on normal or eczematous skin and usually disappears within a few hours. Symptoms cover a spectrum (Table 17.1a). At the weakest end, patients may experience itching, tingling, or burning accompanied by erythema (wheal and flare). At the more extreme end of the spectrum, extracutaneous symptoms may accompany the local urticarial response, ranging from rhinoconjunctivitis to anaphylactic shock.2 The mechanisms underlying contact urticaria are divided into three main types; namely, immunologic (IgE mediated), nonimmunologic, and unclassified3 (Table 17.1b).