Patch Testing in Discoid Eczema

Abstract

Fifty patients of both sexes with clinically suspected discoid eczema were patch tested with the Indian Standard Patch Test Battery approved by the Contact and Occupational Dermatosis Forum of India (CODFI). Most of these patients were young adults between 20 and 39 years old, with a mean age of 36 years. The mean duration of symptoms was 21/2 years. The occupational profiles of the patients included farmers (24%), housewives (18%), students (14%), housewives engaged in farming (12%), shopkeepers (10%), and laborers (8%). The miscellaneous group, including technicians, drivers, cable operators, office workers, and computer operators, accounted for the remaining 14%. The common clinical patterns of presentation of discoid eczema included hands and feet (44%), hands and forearms' (30%), legs and feet (12%) and trunk and limbs (12%). Patch test analysis of these patients revealed that, out of the 50 subjects tested, 28 (56%) reacted to one or more allergens. Potassium dichromate was the most common allergen (20%), followed by nickel (16%), cobalt chloride, and fragrance (12% each) in decreasing order of frequency. Hence, it may be concluded that patch testing should be considered for all patients with severe or persistent discoid eczema because allergic contact dermatitis may be relatively common in such patients and the avoidance of offending allergens may be of substantial benefit to the patients.

Nummular Eczema and Contact Allergy

“…In a series of 4825 patients, patch-tested by 10 dermatologists in 7 European countries, 100 subjects (2.1%) had nummular dermatitis, and 17% of these had relevant positive reactions. 23 Others have reported variable incidence of contact allergy in nummular eczema, ranging from 30.1%, 24 40.6%, 27 50%, 25,26 up to 77.9%. 39 Regardless of such variability from one case series to another, likely a bias from different cohorts numbers, the above data suggest that contact allergy is common in persistent discoid eczema.…”

Hand dermatitis/eczema: Current management strategy

“…A high percentage of these showed clinically‐relevant positive patch tests with rubber, chemicals and metals as the common allergens 67 . In an Indian study on 50 patients with discoid eczema, patch testing analysis showed a positive reaction to allergens in 56%, with potassium dichromate as the most common allergen (20%), followed by nickel (16%), cobalt chloride and fragrances (12% each) 68 . Discoid eczema may be recognized in three different patterns: (i) hands and forearms; (ii) limbs and trunk; and (iii) dry discoid eczema.…”

Role of contact allergens in chronicity and relapses of nummular eczema

“…19 Potassium dichromate was the most common allergen (20%), followed by nickel (16%), cobalt chloride and fragrance mix (12% each) in decreasing order of frequency.…”

“…20% and 16% respectively; whereas in our series five (12.5%) patients were sensitive to nickel. 19 Allergy to components of topical preparations is common in patients suffering from chronic dermatitis. Pasricha et al reported contact sensitivity to neomycin in 28% of their patients of suspected medicament contact dermatitis.…”