Patch Test Clinic Research Articles

CD08 Double bubble trouble

Abstract A 29-year-old woman of Lithuanian heritage was referred to dermatology with a 3-year history of recurrent blistering to the hands and, occasionally, feet. The patient’s own photographs revealed small, tense blisters on the sides of her fingers and one on the foot. In the general dermatology clinic, she was noted to have acrylic nails, which she had been applying at home with her own gel nail kit for over 5 years. In recent years, the patient had noticed that use of the acrylic nail kit exacerbated her blistering. There was no prior history of skin disease or atopy. She was otherwise well, with no known allergies. She worked in the food-packing industry where she wore nonlatex gloves. In light of her frequent, prolonged use of acrylic nails and exacerbation of blistering on use of the home kit, she was suspected to have allergic contact dermatitis (ACD) to acrylates and was referred to the patch test clinic. Patch testing was performed to the British standard, facial, rubber and acrylate series. She had positive reactions to five different acrylates, confirming a clinical diagnosis of ACD relevant to her use of acrylic nails and gel polish. However, she was noted to have several unusual features. Clinically, she had small round scars on the dorsum of both hands. On questioning, she described scars occurring after each blister. Blisters occurred all year round but were significantly more frequent in the summer months. Exposure of her gel nails to ultraviolet (UV) light was felt to trigger the blistering. This prompted additional tests to investigate possible photosensitivity. Both urine and plasma porphyrin levels were significantly elevated, confirming cutaneous porphyria. This is an unusual case of a dual pathology causing blistering of the hands: ACD to acrylates and cutaneous porphyria. In most circumstances, it is ACD that is the overlooked diagnosis, but here, an important general medical diagnosis may have been missed. It is important to remember that blistering caused by gel nail kits may be multifactorial, with acrylates causing ACD and UV light possibly triggering cutaneous porphyria.

Patient-Centered Communication Tools for the Patch Test Clinic.

Patient-centered communication positively impacts the clinical encounter. Multiple strategies exist to improve communication between providers and their patients; the application and impact of these strategies have been studied in multiple specialties, though little exists regarding communication best practices in the patch test clinic. Because the procedural components of patch testing often span the course of an entire week, effective communication with patients during the patch testing visit is important for not only technical success, but also patient understanding and experience. In this study, we highlight the value of beginning the patch testing visit with clear introductions and agenda setting, improving patient understanding and engagement through methods such as teach backs and cycles of questions and answers that create patient-provider dialogue, and using communication techniques to make expressions of empathy. We provide detailed examples regarding the application of these techniques to the patch testing process, aimed at enhancing the patch testing experience and improving clinical outcomes. Our review exemplifies how dermatologists can leverage communication tools to improve patient satisfaction and outcomes during patch testing.

Trends in the Prevalence of Methylchloroisothiazolinone/Methylisothiazolinone Contact Allergy in North America and Europe

The common use of isothiazolinones as preservatives is a global cause of allergic contact dermatitis. Differences in allowable concentrations of methylisothiazolinone (MI) exist in Europe, Canada, and the US. To compare the prevalence of positive patch test reactions to the methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) combination and MI alone in North America and Europe from 2009 to 2018. This retrospective analysis of North American Contact Dermatitis Group, European Surveillance System on Contact Allergies (ESSCA), and the Information Network of Departments of Dermatology (IVDK) databases included data from patients presenting for patch testing at referral patch test clinics in North America and Europe. Patch tests to MCI/MI and MI. Prevalence of allergic contact dermatitis to MCI/MI and MI. From 2009 to 2018, participating sites in North America and Europe patch tested a total of 226 161 individuals to MCI/MI and 118 779 to MI. In Europe, positivity to MCI/MI peaked during 2013 and 2014 at 7.6% (ESSCA) and 5.4% (IVDK) before decreasing to 4.4% (ESSCA) and 3.2% (IVDK) during 2017 and 2018. Positive reactions to MI were 5.5% (ESSCA) and 3.4% (IVDK) during 2017 and 2018. In North America, the frequency of positivity to MCI/MI increased steadily through the study period, reaching 10.8% for MCI/MI during 2017 and 2018. Positive reactions to MI were 15.0% during 2017 and 2018. The study results suggest that in contrast to the continued increase in North America, isothiazolinone allergy is decreasing in Europe. This trend may coincide with earlier and more stringent government regulation of MI in Europe.

Contact allergy to hydroxyisohexyl 3-cyclohexene carboxaldehyde in Italy: Prevalence, trend, and concordance with fragrance mix II.

Hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC), contained in fragrance mix II (FM II), has been recognized as a contact sensitizer since the mid-1990s. After several attempts to reduce its use during the last two decades, HICC was permanently banned from the European market in August 2021. To assess the prevalence and the time trend of contact allergy to HICC and to investigate the concordance of HICC allergy compared to FM II allergy in an unselected Italian patch test population. Retrospective analysis on demographics and patch test results of HICC-sensitized and/or FM II-sensitized patients was performed over a 6-year period (2016-2021) at 6 patch test Clinics in Italy. Among 7266 patients (4942 females, 68.0%, mean age 45.4 ± 20.6 years), 1% (70) resulted positive to HICC and 2.1% (153) to FM II. Clinical relevance was documented in 72.9% (51/70) of HICC positive patients. Among the 169 HICC and/or FM II positive patients, 9.5% had a positive reaction to HICC only, 31.9% to both HICC and FM II, and 58.6% to FM II only. The prevalence trend line of HICC positive reactions showed a decrease from 1.15% (2016) to 0.96% (2021). We documented a decreasing trend of HICC allergy in Italy, in line with the data recently reported in literature. Nevertheless, HICC should be maintained in the baseline series to monitor the benefits of its ban from the European market.

Contact allergy to metals in metalworkers: A systematic review and meta-analysis.

Occupational hand eczema is frequent in metalworkers. The contribution of metal allergies is poorly elucidated even though such exposures are common at the workplace. To estimate the prevalence of metal allergy to cobalt (Co), chromium (Cr) and nickel (Ni) in metalworkers and compare these to estimates from the European Surveillance System on Contact Allergies (ESSCA). Two authors independently searched PubMed for studies reporting on the prevalence of metal allergy in metalworkers. Proportion meta-analyses were performed to calculate the pooled proportions of metal allergy in metalworkers. In total, 29 studies (22 from Europe) were included yielding 5691 subjects for quantitative analysis. The pooled proportion (95% confidence interval) of Co, Cr and Ni in European metalworkers with dermatitis referred to patch test clinics was 8.2% (5.3%-11.7%), 8.0% (5.1%-11.4%), and 11.0% (7.3%-15.4%), respectively. The corresponding estimates for unselected metalworkers from workplace studies were 4.9% (2.4%-8.1%), 5.2% (1.0%-12.6%), and 7.6% (3.8%-12.6%), respectively. In comparison, the prevalence of metal allergy in 13 382 consecutive European males with dermatitis was 3.9% (3.6%-4.2%), 4.4% (4.1%-4.8%) and 6.7% (6.3%-7.0%) for Co, Cr and Ni, respectively. Data on sex, age, body piercings and atopic dermatitis in metalworkers with metal allergy was mostly lacking. Metal allergy to all three metals was significantly more common in European metalworkers with dermatitis attending patch test clinics as compared to ESSCA data, indicating a relationship to occupational exposures, however, confounders could not be accounted for.

Prevalence of Contact Allergy to Nickel: A Retrospective Chart Review.

No recent studies reporting nickel sensitivity prevalence in Canadians exist. The aim of this study was to quantify nickel sensitivity prevalence in patients at a patch test clinic in Vancouver. Retrospective chart review of 3263 patients patch tested for nickel sensitivity at our clinic in Vancouver between 2008 and 2020. In total, 24.3% (n = 792 of 3263) of patients were sensitive to nickel. Nickel sensitivity significantly increased over time from 24.3% to 27.9% from 2008 to 2020. Nickel-sensitive patients were significantly more likely to be women (P < 0.001), between the ages of 19 and 64 years (P = 0.010), and have dermatitis affecting the face (P = 0.001) and hands (P = 0.001). Nickel-sensitive patients were significantly less likely to be 65 years or older (P = 0.001) and have dermatitis affecting the legs (P = 0.002). Approximately half of nickel-sensitive reactions were new positive reactions at the second reading. Nickel sensitivity occurred in approximately one quarter of patients and significantly increased over time. Nickel-sensitive patients were more likely to be women, aged 19 to 64 years, and have dermatitis affecting the face and hands; and less likely to be 65 years or older and have dermatitis affecting the legs.

Allergic contact dermatitis in healthcare workers.

Allergic contact dermatitis is a common occupational skin disease among healthcare workers (HCWs). This study describes causes of allergic contact dermatitis in New Zealand HCWs. All HCWs undergoing patch testing between July 2008 and January 2020 at a public hospital patch test clinic and between June 2019 and January 2020 at a private dermatology clinic were included. Data collected included patient demographics, occupation, results of patch testing and pre- and post-patch test diagnoses. Out of 837 patients tested, 67 were HCWs. The mean age of HCWs was 41 years (SD 14) and 58 (87%) were female. The most common occupations were nurses (40%), allied health (22%) and doctors (18%). Forty-six (69%) patients had a background of atopic dermatitis. Hand dermatitis was the most common presentation (49%), followed by facial/neck dermatitis (25%). Thirty-eight (57%) had at least one positive reaction on patch testing, including 19 (28%) with a positive result of current relevance. There were 16 relevant reactions to rubber accelerators, 11 to fragrances, 10 to preservatives and 6 to corticosteroids. The most frequent relevant allergens were methylisothiazolinone/methylchloroisothiazolinone (4%), hydroxyisohexyl 3-cyclohexene carboxaldehyde (4%) and methylisothiazolinone (4%). The most common allergens in HCWs were rubber chemicals, fragrances, preservatives and topical corticosteroids. Important allergens for patch testing HCWs are outlined, in particular, those with hand dermatitis should be tested to a rubber series.

Update on Contact Sensitization in the Older Adult Population.

Little is known about the epidemiology of allergic contact dermatitis in the aging US population. The aim of this study was to describe patch test results in a cohort of older adult patients evaluated in a patch testing clinic in a tertiary medical center. This study was a retrospective analysis of patch test results of adults 65 years and older from February 2013 to December 2019. Data from a total of 169 patients 65 years and older were analyzed. Of these patients, 84.6% (143/169) had 1 or more positive reactions on patch testing, 84.6% (121/143) of which were felt to be clinically relevant and received a final diagnosis of allergic contact dermatitis. The most common allergen categories were fragrances (30.1%), preservatives (20.8%), metals (11.0%), medicaments (8.3%), and textile dyes (6.5%). The most common individual allergens were Myroxylon pereirae resin (balsam of Peru), hydroperoxide of linalool, methylisothiazolinone, nickel sulfate, and fragrance mix I. Personal products were by far the most common presumed source of allergen exposure. Allergic contact dermatitis is a common diagnosis in the older adult population, and patch testing with allergen avoidance counseling can be an important diagnostic step and potential cure for this allergic condition.

Prevalence of contact allergies in the population compared to a tertiary referral patch test clinic in Jena/Germany.

The contact allergy prevalences in patch-tested patients are usually higher than those in the population, owing to morbidity-driven selection. To examine the differences between two samples, one from the population, one from the patch test clinic, in one area of Germany (Jena, Thuringia). Between August 2008 and October 2011, a total of 519 participants of the population-based european dermato-epidemiology network (EDEN) fragrance study were patch tested in Jena using a TRUE Test baseline series extended with some pet.-based (fragrance) allergen preparations. Between 2007 and 2012 (inclusive), 1906 routine patients were patch tested for suspected allergic contact dermatitis (ACD) in the Jena University Hospital Department; of these 1694 (83.2%) with the German baseline series using pet./aq.-based, investigator-loaded allergens. In the population (clinical) sample, 19.6% (41.1%) were sensitized to at least one of the allergens considered. The most common baseline series allergens in the population/clinical sample were nickel (10.5%/13.2%), fragrance mix (FM) II (2.9%/6.7%), FM I (2.3%/8.3%), and cobalt (1.6%/5%). The clinical sample was slightly older (71.5% vs 55.9% age 40+) and included less males (36% vs 49.3%). Results are quite similar, although prevalences are usually higher in the clinical setting, with the exception of p-tert-butylphenol formaldehyde resin.

Approach to allergic contact dermatitis caused by topical medicaments.

To provide an approach to identifying topical medicament ingredients that cause allergic contact dermatitis (ACD) and to recognizing common clinical scenarios in which these ingredients might present. A retrospective chart review was conducted of patients patch tested at the Contact Dermatitis Clinic at St Paul's Hospital in Vancouver, BC, between November 2016 and June 2019. Data from the North American Contact Dermatitis Group from 2015 to 2016 and The Ottawa Hospital patch test clinic from 2000 to 2010 were also reviewed. Topical antibiotics are the most common cause of ACD to medicaments and frequently cause cosensitization to multiple allergens. This hypersensitivity reaction is often seen following surgical procedures and should be distinguished from postoperative infection. Corticosteroid allergy is easy to miss and should be suspected in cases of corticosteroid-sensitive dermatoses that worsen despite appropriate treatment. Topical anesthetics and propylene glycol are other causes of ACD found in many prescription and over-the-counter products. Allergic contact dermatitis is easy to miss and should always be considered in cases of eczematous eruptions. A thorough drug history including all topical products-both prescription and over-the-counter-is critical. Patch testing can help identify specific allergens for the patient to avoid.

Patch testing of budesonide in Italy: The SIDAPA baseline series experience, 2018-2019.

Budesonide was included in the European Baseline Series in 2000 as the most suitable marker forcorticosteroid hypersensitivity. In the last two decades, a decreasing trend of budesonide allergy has been observed. To estimate the prevalence of positive patch test reactions to budesonide in a large, Italian patch test population, characterizing patients according to MOAHLFA index and evaluating the benefit with extended readings of budesonide patch test. Retrospective analysis of patient demographics and patch test results over a 2-year period (2018-2019) was performed at 14 patch test clinics in Italy. Ninety out of 14 544 (0.6%) patients reacted to budesonide 0.01% pet.. Positive reactions were mild in 54.4% and late readings at day 7 showed new positive reactions in 37.8% of patients. The MOAHLFA index showed a significant positive association with male gender, atopic dermatitis, and age >40 years and a significant negative association with hand and face dermatitis. We documented a low prevalence of budesonide allergy in Italy, confirming its decreasing trend recently reported in the literature. Nevertheless, budesonide needs to be maintained in the baseline series for its good ability to detect corticosteroid sensitization.

Value of photo assessment in late patch test readings-A multicenter study from six European patch test clinics.

It is recommended that patch test readings include a day (D)7 reading. Substitution of the D7 reading with a photo may be a valid option. To compare the sensitivity of digital photos at D7 to clinical readings, to assess the number of positive reactions appearing at D7 only (late reactions), and after D7 only (delayed reactions). Patients patch tested in six European clinics were instructed to forward photos of the patch test reactions to the respective clinics at D7 (before attending the clinic) and at D21. Only allergens in the baseline series or TRUE Test were included in the data analysis. Two hundred ninety-three of 629 patients had a total of 599 positive reactions, with 6.3% occurring at D7 only. When substituting the D7 reading with a photo (90% submitted), 26.3% of late reactions were missed and nine false-positive reactions were found. Delayed reactions were detected in four patients at D21 (65.3% submitted). Our data show that if the D7 reading is not performed, 6.3% of positive reactions from the baseline series would be missed, and if substituting the D7 reading by digital photo, 26.3% late reactions would be missed. Delayed reactions seemed rare.

Patch Test Clinic Start-up: From Basics to Pearls.

Allergic contact dermatitis is a prevalent burdensome condition affecting millions of Americans. Patch testing, the criterion-standard allergic contact dermatitis diagnostic tool, is underused by US dermatologists. Incorporating patch testing into modern dermatology practices is achievable with utilization of accurate resources and sustainable support. This review focuses on the basics of patch testing and provides practical pearls to assist novice providers in establishing a contact dermatitis specialty practice.

Allergic Contact Dermatitis of the Anogenital Region in Men and Women.

Allergic contact dermatitis is an uncommon but important cause of skin disease in the anogenital region. Relevant allergens are described in women and less commonly in men. The aim of this study was to describe outcomes of patch testing in men and women presenting with anogenital dermatoses. Cases patch tested for anogenital conditions at 2 patch test clinics in Sydney, Australia, from 2002 to 2017 were reviewed. Positive and relevant patch test reactions were recorded. Thirty-seven women and 27 men were included. Dermatitis was the most common diagnosis, followed by psoriasis and lichen sclerosus. Thirty percent had a final diagnosis of allergic contact dermatitis. The most frequent relevant allergens were fragrance mix I (9%), patients own products (9%), Myroxylon pereirae (8%), cocamidopropyl betaine (3%), and benzocaine (3%). The top positive and relevant allergens seen were in concordance with other reports from Australia and the rest of the world. Fragrances and medicaments are common allergens, and it is recommended that products used on anogenital skin be fragrance free. Testing patients own products is imperative.

Findings from a regional U.K. patch-testing clinic for anogenital dermatoses

Findings from a regional U.K. patch-testing clinic for anogenital dermatoses

266 Nickel coreactions and polysensitization to metals in adults

Allergic contact dermatitis to metals is a significant clinical and public health problem. Some patients may be sensitized to multiple metals, thereby complicating allergen avoidance strategies by patients and manufacturers. However, little is known about the frequency and predictors of polysensitization to metals. We sought to determine the frequency of ≥1 metal coreactions to nickel and metal polysensitization (positive reactions to ≥2 different metals). We performed a retrospective chart review of 484 adults (age ≥ 18, mean±sd: 46.7±14.6 years), who were patch-tested at the Northwestern Medicine patch-testing clinic from 2014-2017. Patients were patch-tested with the North American Contact Dermatitis Group (NACDG) standard series and supplemental metal series if indicated. Positive patch test reactions to ≥ 1 metal allergen were observed in 210 (43.3%) of patients, with nickel (19.1%), gold (11.8%) and palladium (11.1%) being most common. Among patients with positive reactions to nickel, 38.0%, 16.3% and 2.2% had positive reactions to 1, 2 or 3 additional metals, respectively. Overall, polysensitization to metals occurred in 13.9% of patients. In multivariable multinomial logistic regression models, polysensitization to metal allergens was associated with female sex (adjusted odds ratio [95% confidence interval]: 10.23 [2.38-43.98]) and polysensitization to non-metal allergens (2.07 [1.01-4.23]), inversely associated with older age (0.94 [0.92-0.97]), but not associated with non-white race/ethnicity (1.24 [0.62-2.48]) or birthplace outside the US (1.11 [0.48-2.55]). These results suggest that nickel-sensitized patients have high rates of metal co-reactions, and that polysensitization to metals is common. These results may help guide future strategies for allergen avoidance.

Patch test clinic experience of potential cross-reactivity of isothiazolinones.

Patch test clinic experience of potential cross-reactivity of isothiazolinones.

Frequency and trends of contact allergy to and iatrogenic contact dermatitis caused by topical drugs over a 25-year period.

Allergic contact dermatitis is the most common adverse reaction caused by topical drugs. To study the demographic characteristics and lesion locations of patients with iatrogenic dermatitis, and to analyse contact allergy to active principles and trends in frequencies over the years. Between 1990 and 2014, 14 911 patients were patch tested with the European baseline series. Patients with a presumed iatrogenic cause were often tested with a pharmaceutical series, and, if indicated, with photo-patch tests. Most were also tested with the topical products to which they had been exposed, along with their ingredients. Eight thousand three hundred and seventy-four (56%) patients tested positively, and 2600 (17.4%, 95%CI: 16.8-18.0%) of all patients suffered from iatrogenic contact dermatitis. The most important primary sites of dermatitis were the legs, face, and hands. The most common sensitizers included topical antibiotics, antiseptics, and corticosteroids. The most frequent baseline allergens in this subgroup were budesonide, neomycin, and benzocaine, although with a decreasing trend over the years. Many other allergens from different pharmacological classes were identified. With a prevalence of 17.4% of consecutive patients, iatrogenic contact dermatitis is a frequent diagnosis in patients attending a general patch test clinic, involving one-third of the patients with at least one positive reaction.

Contact allergy to rubber accelerators remains prevalent: retrospective results from a tertiary clinic suggesting an association with facial dermatitis

Chemicals used for the manufacturing of rubber are known causes of allergic contact dermatitis on the hands. Recent European studies have suggested a decrease in thiuram contact allergy. Moreover, while an association with hand dermatitis is well established, we have recently observed several clinical cases with allergic facial dermatitis to rubber. To evaluate temporal trends of contact allergy to rubber accelerators from the European baseline series in a tertiary patch test clinic in Denmark, and examine associations with anatomical locations of dermatitis. Patch test and clinical data collected in a Danish tertiary dermatology clinic in Gentofte, Herlev, Copenhagen between 1 January 2005 and 31 December 2014 were analysed. The following rubber accelerators or mixtures in petrolatum from the European baseline patch test series were included: thiuram mix 1.0%, mercaptobenzothiazole 2.0% and mercapto mix 1.0%. The overall prevalence of contact allergy to rubber accelerators was 3.1% with no significant change during the study period (Ptrend = 0.667). Contact allergy to thiuram mix was the most prevalent and was significantly associated with occupational contact dermatitis, hand dermatitis, age >40 years and facial dermatitis in adjusted binary logistic regression analysis. Current clinical relevance of contact allergy to thiuram mix was 59.3%. Patients with contact allergy to mercapto mix and mercaptobenzothiazole had a concomitant reaction to thiuram mix in 35.2% (19/54) and 35.4% (17/48) of the cases respectively. Contact allergy to rubber accelerators remains prevalent. Clinicians should be aware of the hitherto unexplored clinical association with facial dermatitis.

Lack of Association Between Dust Mite Sensitivity and Atopic Dermatitis.

Dust mites (DMs) play a role in type I respiratory allergy. Studies relating to DM irritant versus immune reactions are somewhat conflicting in atopic dermatitis (AD). The aim of this study was to assess the diagnostic use of patch testing to DM in patients with AD and other dermatitides. We performed a prospective study of 323 adults recruited in a patch testing clinic. Patch testing antigens were DM extract (0.01%, 0.1%, 1%, 10%, and 20% in petrolatum; Chemotechnique) and/or 200 index of reactivity in petrolatum (Stallergenes). Patches were placed and read at 48 hours with delayed readings after 72 to 168 hours. There was no association of DM positivity with AD, asthma, hay fever, or demographic factors. There was no association of DM positivity with the clinical diagnosis or phenotype. The number of positive (+, ++, and +++) and doubtful reactions to Chemotechnique DM extract increased with higher concentrations. Positive reactions to DM had a morphological appearance characterized by numerous discrete erythematous papules and, rarely, papulovesicles. Positive reactions to Stallergenes DM 200 IR were infrequent and all weak reactions, similar to DM 0.01%. Patch testing to DM does not seem to have clinical use for determining the etiology of dermatitis.