S3 guidelines: Epicutaneous patch testing with contact allergens and drugs – Short version, Part 1

Abstract

Summary Epicutaneous patch testing is the diagnostic standard for the detection of allergic contact dermatitis. The present guidelines are aimed at residents and board‐certified physicians in the fields of dermatology and allergology as well as other medical specialties involved in establishing the indication for patch testing and its execution in patients with contact dermatitis and other forms of delayed‐type hypersensitivity. The target audience also includes other health care providers and insurance funds. Based on a systematic literature search and a formal consensus process (S3), the guidelines were developed by dermatologists in collaboration with pediatricians, occupational medicine physicians, nursing staff as well as patient representatives. The systematic methodological approach and appraisal of evidence upon which the recommendations are based are outlined in a separate method report that also contains evidence tables. The guidelines address general aspects of patch testing as well as medicolegal issues. The recommendations given relate to topics such as the indication for patch testing, informed patient consent, as well as the choice of test substances, test chambers and test site, duration of exposure, reading times and interpretation of test reactions. Furthermore, recommendations are provided with respect to endogenous and exogenous factors, specific patient groups (children, pregnant women, immunosuppressed individuals) as well as possible risks and adverse events associated with patch testing using contact allergens. Note: This publication is part 1 of the short version of the S3 guidelines for “Epicutaneous patch testing using contact allergens and drugs” (registry no. 013 – 018; date: March 20, 2019; valid until December 31, 2021). Part 2 of the short version will be published in the next issue. The long version of these guidelines can be accessed at http://www.awmf.org. The method report is available as online publication (https://www.awmf.org/leitlinien/detail/ll/013-018.html) and contains the evidence tables in its appendix.

Contact sensitization in metalworkers: Data from the information network of departments of dermatology (IVDK), 2010–2018

“…Patch testing and evaluation of reactions are performed according to DKG guidelines. 14,15 For the present data analysis, patch test reactions at day 3 (D3) were considered. In a few exceptional cases, when a PT reading was performed at D4 instead of D3, this reading From January 2010 to December 2018, a total of 107 288 patients were patch tested in the departments of dermatology which are members of the IVDK.…”

“…All IVDK members are also members of the German Contact Dermatitis Research Group (DKG). Patch testing and evaluation of reactions are performed according to DKG guidelines 14,15 . For the present data analysis, patch test reactions at day 3 (D3) were considered.…”

Optical coherence tomography for patch test grading: A prospective study on its use for noninvasive diagnosis of allergic contact dermatitis

“…Patch testing was performed according to the international and German guidelines on the upper back and removed after 48 hours. Conclusive grading was performed following the German guidelines after 3 days, and also after 7 or 10 days for aminoglycosides, p ‐phenylenediamine, and metals 6 …”

“…Reported specificity and sensitivity range between 70% and 80% depending on the tested substance 4 . According to the scoring system, developed by the International Contact Dermatitis Research Group (ICDRG), the reaction in patch testing is classified into six groups based on the specified morphological criteria, ranging from no reaction (0) to extreme positive bullous reaction (+++), with additionally doubtful (?+) and irritant reactions (IR) 5,6 . A drawback of patch testing is that the interpretation of the results is usually influenced by the observer; hence it is not fully objective 5,7,8 .…”

‘The need for dose–response studies: time for a reminder?’ – reply from the authors

“…The SLS concentration of 0·25% in aqua proved to be most suitable for this important discrimination. Aiming to help the dermatologist with these difficult‐to‐interpret test reactions, an additional SLS skin test was introduced as ‘irritant control’ to the German patch test baseline series from 2008 on 5 …”