Contact allergy and allergic contact dermatitis

Contact allergy is specific hypersensitivity reaction of delayed type to low molecular weight substances, referred to as haptens. The hypersensitivity is induced by a direct exposure of the skin to the hapten with a range of co-factors required to breach immune tolerance. Subsequent reactions may be provoked either by direct contact to the skin or by systemic exposure. The most frequent clinical manifestation of contact allergy is allergic contact dermatitis (ACD), which is among the three most common diseases from the spectrum of eczema. As various eczemas frequently co-exist and are very hard (or even impossible) to differentiate based merely upon clinical symptoms, the diagnosis of ACD should be considered in each case of chronic or recurrent eczema, including routine patch testing. The present article discusses the current knowledge on the pathomechanisms and clinical picture of ACD. Patch test is the only method available and a gold standard for the detection of contact allergy and diagnosis of the ACD. In Poland, the mainstay of the routine diagnosis of patients with eczema is the Polish Baseline Series, which is discussed here along with its recent updates. Additional testing according to patient's exposure is always to be considered, with special attention required to patient's own topical drugs and cosmetics, including emollients and moisturizers. Furthermore, the treatment options for ACD are discussed with stressing the importance of avoiding offending haptens as the first line of therapy. (C) 2014 Polish Society of Allergology. Published by Elsevier Urban & Partner Sp. z o.o.All rights reserved.