Patch test results in patients with suspected contact allergy to shoes: Retrospective IVDK data analysis 2009–2018

Abstract

Background: Allergic contact dermatitis caused by shoes is common and new relevant allergens have been identified.Objectives: To investigate the pattern of type IV sensitization in patients with suspected allergic contact dermatitis of the feet related to shoes as a presumed culprit trigger.Methods: Retrospective analysis of data of the Information Network of Departments of Dermatology (IVDK), 2009-2018.Results: Six hundred twenty-five patients with presumed shoe dermatitis were identified in a cohort of 119 417 patients. Compared to patients with suspected contact sensitization from other allergen sources (n = 118 792), study group patients were more frequently sensitized to potassium dichromate (10.8% vs 3.5%), colophony (7.2% vs 3.7%), mercaptobenzothiazole (MBT; 4.0% vs 0.6%), mercapto mix (4.6% vs 0.6%), and p-tert-butylphenol formaldehyde resin (1.6% vs 0.5%). Sensitizations to urea formaldehyde resin, melamine formaldehyde resin, glutaraldehyde, tricresyl phosphate, and phenyl glycidylether were rare. Moreover, reactions to compounds in the leather or textile dyes test series were scarce. Conclusion:A distinct sensitization pattern was observed in patients with suspected allergy to shoe materials. Although substances with low sensitization rates should be removed from the leather and shoe patch-test series, novel potential allergens should be added.

Tracing colophonium in consumer products

“…Colophonium is a well‐known cause of shoe allergy in glues and finishes or as tackifier. The frequency of sensitization to colophonium in patients with foot dermatitis was about twice as high as in the control group of patients with suspected contact sensitization to other allergen sources and comparable to earlier data according to a new retrospective study from the IVDK (Information Network of Departments of Dermatology) 27 . It should be noted that colophonium in shoes is often modified by esterification or Diels‐Alder reactions, whereby new strong sensitizers are formed that do not cross‐react with the haptens in unmodified colophonium 15,25,28,29 …”

“…Departments of Dermatology). 27 It should be noted that colophonium in shoes is often modified by esterification or Diels-Alder reactions, whereby new strong sensitizers are formed that do not cross-react with the haptens in unmodified colophonium. 15,25,28,29 Because colophonium is a natural product, nontoxic and with very good adhesive properties, it finds usage when technical devices are fastened to the skin, such as insulin-infusion sets.…”

The Value of Patch Testing With Shoe Material Samples in Patients Suspected of Shoe Allergic Contact Dermatitis

“…Three patients with relevant positive reactions to PPD were probably caused by dyes in black rubber and leather shoes. However, previous studies reported that shoe ACD from dyes was rare 5,23 . Chemical analysis of shoe materials should be done to confirm the clinical relevance of positive reactions as patients may have become sensitized to PPD through different exposures.…”

“…Moreover, patch testing with material samples would help to detect allergic reactions caused by unknown allergens or allergens not commercially available as test substance. There were new allergens that have been discovered by patch testing and analysis of material samples, such as isobornyl acrylate in glucose sensors and insulin pump 5,35 . Recently, Raison-Peyron et al 36 reported acetophenone azine as a new allergen that was responsible for severe contact dermatitis from shin pads.…”

“…Given that the prevalence of suspected shoe ACD at our clinic is low, patch testing with materials taken from patients' shoes is frequently performed to raise the diagnostic rate of shoe ACD. Previous studies have reported the prevalence of positive patch-test reactions to shoe pieces in patients with suspected contact allergies of the feet ranging from 11.8% to 18.7% 1,5 …”