10 years' experience of patch testing with a shoe series in 230 patients: which allergens are important?

Abstract

Over a 10-year period, 230 patients with foot dermatitis were patch tested to a shoe series of allergens. About 54 (23%) had relevant allergic positive reactions to one or more allergens. The commonest relevant allergens groups were, in order, chromate, medicaments, rubber chemicals, dyes and cosmetic constituents, with the most frequent individual allergens being chromate (4%), neomycin (3%), rubber chemicals (> 3%), paraphenylenediamine (2%) and tixocortyl pivolate (2%). Some allergens previously thought to be important, e.g. certain plastic and adhesive chemicals, did not show any positives over the period of study. In addition, para-tertiary butyl phenol formaldehyde resin was a relatively unimportant allergen in this series. The main practical points to emerge from this study are that, in patients with foot dermatitis, chromate is still the principal allergen, and that medicament and cosmetic allergens may be prominent.

Shoe Allergens: Retrospective Analysis of Cross-Sectional Data from the North American Contact Dermatitis Group, 2001-2004

“…31 In this study of NACDG patients, only hexavalent potassium dichromate was tested and was found to be the second most frequent shoe-related allergen, accounting for 17.5% of positive reactions. European, 7,8,13,17 Mediterranean, 18 and Indian 2,21 studies of patients with foot dermatitis found potassium dichromate to be the most frequent allergen, accounting for 10.0 to 43.0% of relevant positive reactions. When the data from published studies were pooled, potassium dichromate was the most frequent individual allergen, accounting for 31.5% of reactions.…”

“…The NACDG standard series also contains few dyes; 4-aminoazobenzene, Disperse Orange 3, Disperse Yellow 3, and Disperse Red 1 were all responsible for a number of allergic reactions in other studies. 2,7,8,10,15,18,19 Dodecylmercaptan, an adhesive, accounted for 1.4 to 4.8% of relevant positive reactions in four studies of suspected footwear dermatitis. 2,8,10,19 Diphenylthiourea, an accelerator used in the manufacture of neoprene, caused four positive reactions in the study by Trattner and colleagues.…”

“…Hydroquinone monobenzylether, benzoyl peroxide, 2-thiocyanomethyl benzothiazole, 2n-octyl-4-isothiazolin-3-one, Desmocoll 400 (Bayer MaterialScience, Leverkusen, Germany), and Desmodur R (Bayer MaterialScience) each accounted for eight or more positive relevant patch-test results in pooled data from other studies. 1,2,7,8,10,12,18,19 There are also numerous published reports of reactions to samples of patients' own shoes. 2,9,14,16,17,20,21,24,25 …”

“…5,6 The most common allergens associated with ACD of the feet vary among studies but are typically those involved in leather or rubber processing. 1,[7][8][9][10] The warm moist environment and occlusion provided by shoes are thought to potentiate the development of ACD. 11 ACD from shoes can be debilitating, and the causative agent may not be obvious.…”

“…Freeman observed that after a mean of 2.9 years from patch testing, 87.5% of 55 patients with footwear dermatitis had improvement or resolution of their symptoms. 9 Studies evaluating the frequency of allergens associated with dermatitis of the feet have been conducted in Europe, 7,8,[12][13][14][15][16][17] the Middle East, 18,19 Asia, 2,20-23 Australia, 9 and regionally in North 1,10,24-26 and South America. 27 To our knowledge, the frequency of allergens associated specifically with a shoe source has not been investigated broadly in North America.…”