Patch test results of hand eczema patients: relation to clinical types.

Background: Allergic contact dermatitis is a well-known cause of hand eczema, although the influence of contact allergens on different clinical types of hand eczema remains still unclear.
Objective: To identify most common positive tested allergens among hand eczema patients and to define the relation between specific contact allergies and clinical types of hand eczema according to the guidelines of the Danish Contact Dermatitis Group (DCDG).
Methods: We included 1571 hand eczema subjects who were patch tested from 1 January 2002 to 31 December 2013. They were retrospectively classified according to the guidelines of the DCDG into six clinical types: recurrent vesicular hand eczema, chronic fissured hand eczema, hyperkeratotic palmar eczema, pulpitis, interdigital eczema and nummular hand eczema according to a newly developed flow chart. The prevalence of sensitizations and association with clinical type, atopic dermatitis, age and gender were studied.
Results: A total of 1395 subjects were classified into one of the six clinical types. The most frequently found clinical types were recurrent vesicular hand eczema (39.7%) and chronic fissured hand eczema (35.5%). Subjects with recurrent vesicular hand eczema were significantly more likely to have a contact allergy (OR 1.55), whereas subjects with hyperkeratotic palmar eczema and pulpitis were less likely to be sensitized (OR 0.51; OR 0.44). Overall, metals (nickel sulphate, cobalt chloride), fragrances and preservatives (methylchloroisothiazoline/methylisothiazoline, methyldibromoglutaronitrile) were the most frequent sensitizers in patients with hand eczema. This did not deviate in the different clinical types, although subjects with recurrent vesicular hand eczema were significantly more frequently sensitized to nickel sulphate and other allergens compared to other clinical types of hand eczema.
Conclusion: In the diagnostic work up of hand eczema subjects with recurrent vesicular hand eczema should be patch tested, especially women of older age, although the need for patch testing in males with hyperkeratotic palmar eczema might be less imperative.
(© 2014 European Academy of Dermatology and Venereology.)