Summary
The present guideline summarizes all aspects of patch testing for the diagnosis of contact allergy in patients suspected of suffering, or having been suffering, from allergic contact ...dermatitis or other delayed‐type hypersensitivity skin and mucosal conditions. Sections with brief descriptions and discussions of different pertinent topics are followed by a highlighted short practical recommendation. Topics comprise, after an introduction with important definitions, materials, technique, modifications of epicutaneous testing, individual factors influencing the patch test outcome or necessitating special considerations, children, patients with occupational contact dermatitis and drug eruptions as special groups, patch testing of materials brought in by the patient, adverse effects of patch testing, and the final evaluation and patient counselling based on this judgement. Finally, short reference is made to aspects of (continuing) medical education and to electronic collection of data for epidemiological surveillance.
Summary
Background Drug patch tests (PTs) can reproduce delayed hypersensitivity to drugs and entail a moderate re‐exposure of patients to offending drugs.
Objectives To determine the value of PTs ...for identifying the responsible drug in severe cutaneous adverse drug reactions (SCARs) such as acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) and Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN).
Methods In a multicentre study, PTs were conducted on patients referred for DRESS, AGEP or SJS/TEN within 1 year of their SCAR. All drugs administered in the 2 months prior to and the week following the onset of the SCAR were tested.
Results Among the 134 patients included (48 male, 86 female; mean age 51·7 years), positive drug PTs were obtained for 24 different drugs. These included positive tests for 64% (46/72) of patients with DRESS, 58% (26/45) of those with AGEP and 24% (4/17) of those with SJS/TEN, with only one relapse of AGEP. The value of PTs depended on the type of drug and the type of SCAR (e.g. carbamazepine was positive in 11/13 DRESS cases but none of the five SJS/TEN cases). PTs were frequently positive for beta lactams (22 cases), pristinamycin (11 cases) and in DRESS with pump proton inhibitors (five cases), but were usually negative for allopurinol and salazopyrin. Of 18 patients with DRESS, eight had virus reactivation and positive PTs. In DRESS, multiple drug reactivity was frequent (18% of cases), with patients remaining sensitized many years later.
Conclusions PTs are useful and safe for identifying agents inducing SCAR.
What’s already known about this topic?
•
Patch tests (PTs) seem to be of value in investigating acute generalized exanthematous pustulosis (AGEP), with a possible role in drug reaction with eosinophilia and systemic symptoms (DRESS) (with a limited number of drugs in one study), but not in toxic epidermal necrolysis.
What does this study add?
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In the largest multicentre study to date, PTs were safe and useful for identifying agents in AGEP and DRESS, e.g. corticosteroids in AGEP or proton pump inhibitors in DRESS.
•
Multiple drug reactivity was frequent in DRESS.
The human repeated insult patch test (HRIPT) has a history of use in the fragrance industry as a component of safety evaluation, exclusively to confirm the absence of skin sensitization at a defined ...dose.
The aim of the study was to document the accumulated experience from more than 30 years of conducting HRIPTs.
A retrospective collation of HRIPT studies carried out to a consistent protocol was undertaken, with each study comprising a minimum of 100 volunteers.
The HRIPT outcomes from 154 studies on 134 substances using 16,512 volunteers were obtained. Most studies confirmed that at the selected induction/challenge dose, sensitization was not induced. In 0.12% of subjects (n = 20), there was induction of allergy. However, in the last 11 years, only 3 (0.03%) of 9854 subjects became sensitized, perhaps because of improved definition of a safe HRIPT dose from the local lymph node assay and other skin sensitization methodologies, as well as more rigorous application of the standard protocol after publication in 2008. This experience with HRIPTs demonstrates that de novo sensitization induction is rare and becoming rarer, but it plays an important role as an indicator that toxicological predictions from nonhuman test methods (in vivo and in vitro methods) can be imperfect.
Background
The Japanese baseline series (JBS), established in 1994, was updated in 2008 and 2015. The JBS 2015 is a modification of the thin‐layer rapid‐use epicutaneous (TRUE) test (SmartPractice ...Denmark, Hillerød, Denmark). No nationwide studies concerning the TRUE test have previously been reported.
Objectives
To determine the prevalence of sensitizations to JBS 2015 allergens from 2015 to 2018.
Methods
We investigated JBS 2015 patch test results using the web‐registered Skin Safety Care Information Network (SSCI‐Net) from April 2015 to March 2019.
Results
Patch test results of 5865 patients were registered from 63 facilities. The five allergens with the highest positivity rates were gold sodium thiosulfate (GST; 25.7%), nickel sulfate (24.5%), urushiol (9.1%), p‐phenylenediamine (PPD; 8.9%), and cobalt chloride (8.4%). The five allergens with the lowest positivity rates were mercaptobenzothiazole (0.8%), formaldehyde (0.9%), paraben mix (1.1%), mercapto mix (1.1%), and PPD black rubber mix (1.4%).
Conclusions
Nickel sulfate and GST had the highest positivity rates. The JBS 2015, including a modified TRUE test, is suitable for baseline series patch testing.
Patch test results of the Japanese baseline series 2015 from 2015 to 2018 for 5865 patients.
The five allergens with the highest positivity rates were gold sodium thiosulfate, nickel sulfate, urushiol, p‐phenylenediamine, and cobalt chloride.
Contact Allergy in Patients with Rosacea Magdaleno-Tapial, J; López-Martí, C; García-Legaz-Martínez, M ...
Actas dermo-sifiliográficas (English ed.),
06/2022, Letnik:
113, Številka:
6
Journal Article
Recenzirano
Rosacea is a chronic acneiform skin disorder in which impaired skin barrier function can lead to sensitization to allergens. We aimed to analyze contact allergies in our patients with rosacea.
...Retrospective cohort study of all patients who underwent patch testing in our skin allergy clinic between May 1991 and May 2019.
A total of 200 patients with rosacea were referred to our clinic for patch testing during the study period; they represented 2.1% of all patch tested patients in the period. Eighty-one percent were women (mean age, 44.7years). At least 1positive patch test was recorded for 46.5%; 15% were of current relevance. The most frequent positive reaction was to nickel (26%), followed by cobalt chloride (6.5%), isothiazolinones (6%), p-phenylenediamine (5.5%), fragrance mixII (5%), and thimerosal (3.5%). The most common currently relevant patch test reactions were to isothiazolinones in 10 of the 200 patients (5%); to phenylenediamine, fragrance mixII, and toluensulfonamide formaldehyde resin in 4 patients (2%) each; and to tixocortol and fragrance mixI in 2 patients (1%) each. The allergen groups most often implicated were metals (of current relevance in 12.6%) and drugs (of current relevance in 25.8%). Preservatives and fragrances were the next most common allergen groups, and 70.8% and 43.7% of the positive reactions in these groups, respectively, were of current relevance. Cosmetics were the most frequent source of sensitization, followed by topical medications - notably corticosteroids and antifungal agents.
We emphasize the high prevalence of allergic contact dermatitis in patients with rosacea, a finding which supports patch testing, especially if eruptions worsen when these patients use cosmetics and topical medications.
Long-lasting allergic patch test reactions (LLAPTR) are reactions that remain positive for two weeks or more after the application of the allergen. LLAPTR of longer than 6 weeks duration is rarely ...seen. Here we present a 54-year-old female patient who had a positive allergic reaction to bacitracin with the thin layer rapid use epicutaneous test (TRUE test), which lasted for about 11 weeks duration. To our knowledge this is the first reported case of LLAPTR related to the bacitracin. (Ann Dermatol 32(4) 331∼333, 2020)
Background
Data regarding teledermatology for patch testing are limited.
Objectives
Compare patch test readings and final interpretation by two in‐person dermatologists (IPDs) with eight ...teledermatologists (TDs).
Methods
Patch tested patients had photographs taken of 70 screening series of allergens at 48 hours and second readings. Eight TDs reviewed photos and graded reactions (negative, irritant, doubtful, +, ++, +++) at 48 hours and second readings; in addition, they coded a final interpretation (allergic, indeterminant, irritant, negative) for each reaction. TDs rated overall image quality and confidence level for each patient and patch test reaction, respectively. Percentage of TD–IPD agreement based on clinical significance (success, indeterminate, and failure) was calculated. Primary outcome was agreement at the second reading.
Results
Data were available for 99, 101, and 66 participants at 48 hours, second reading, and final interpretation, respectively. Pooled failure (+/++/+++ vs negative) at second reading was 13.6% (range 7.9%‐20.4%). Pooled failure at 48 hours and final interpretation was 5.4% (range 2.9%‐6.8%) and 24.6% (range 10.2%‐36.8%), respectively. Confidence in readings was statistically correlated with quality of images and disagreement.
Conclusion
For patch testing, teledermatology has significant limitations including clinically significant pooled failure percentages of 13.6% for second readings and 24.6% for final interpretation.
Eight patch test experts served as store‐forward teledermatologists, grading patch test reactions of 70 allergens in 101 participants.
Pooled failure percentages were 13.6% (second readings: +/++/+++ vs negative) and 24.6% (final interpretation: allergic vs not).
Teledermatology for reading patch test reactions has significant limitations.
Background
Contact allergy rates of linalool and limonene hydroperoxides (HPs) have increased.
Objectives
To demonstrate the patterns of simultaneous positive patch test (PT) reactions and ...prevalences of multiple contact allergies (MCAs) in patients with contact allergy to linalool and/or limonene HPs.
Methods
A retrospective analysis of consecutive dermatitis patients in 2015–2020 was performed.
Results
Of all 4192 patients, 1851 had at least one positive PT reaction. Of these, 410 (22.2%) had MCAs, significantly related to a higher age (p‐value = 0.003). Patients with an exclusively positive reaction to linalool HPs but not limonene HPs were shown to have MCAs (p‐value <0.001, odds ratio (95% confidence interval) = 4.15 (3.01–5.73)). Patients with simultaneous contact allergies to both linalool and limonene HPs had contact allergies to many other screening and fragrance allergens.
Conclusions
Simultaneous positive PT reactions to allergens in baseline series and fragrances are common in patients with the HPs contact allergy, especially linalool HPs. The pattern of simultaneous PT reactions principally suggested the co‐sensitization of the cosmetic allergens.
Patients with an exclusively positive reaction to linalool hydroperoxides (HPs) significantly had multiple contact allergies, and patients with simultaneous contact allergies to both linalool and limonene HPs had contact allergies to many other screening and fragrance allergens. The pattern of simultaneous positive reactions suggested the co‐sensitization of the cosmetic allergens.
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