Contact allergy in a paediatric population observed in a tertiary referral centre in Belgium.

BACKGROUND: Contact allergy is increasingly recognized as being important in children with eczema. OBJECTIVES: To retrospectively analyse the patch test results in children over the past 10 years, aiming to (1) evaluate demographic characteristics and lesion locations, (2) describe frequencies of positive patch test reactions, and (3) investigate the relationship with atopic dermatitis (AD). METHODS: A total of 329 children were patch tested between January 2010 and December 2019 with the European (children) baseline series and/or other series, and the personal product(s) used. RESULTS: A total of 119 (36%) children presented with at least one positive reaction. Children with AD had a higher prevalence of positive reactions compared with the non-AD group (P = .002), but without statistically significant difference regarding sensitization to more than one hapten (P = .39). The face (20.2%), hands (19.3%), feet (16.8%), arms (12.6%), and body folds (10.9%) were the most common sites of primary localizations. The most frequent contact allergens were nickel sulfate and linalool hydroperoxide (both 16%), limonene hydroperoxide (13.5%), and para-phenylenediamine (10.9%). No statistically significant difference for nickel sulfate was found between the AD and non-AD group (P = .20). CONCLUSIONS: Contact allergy in children with eczema was frequently observed in our tertiary referral centre in Belgium as well, confirming the need for patch testing.

Iatrogenic allergic contact dermatitis in the (peri)anal and genital area.

BACKGROUND: Allergic contact dermatitis (ACD) from topical medication often occurs in occluded areas, for example, with wound treatment, but also in certain body locations, such as the anogenital area. OBJECTIVES: To investigate the demographics and specific lesion location of patients with ACD from topical drugs applied onto the (peri)anal/genital area, and to identify the respective causal topical pharmaceutical products and ingredients involved. METHODS: From January 2000 to December 10, 2018, 532 patients were tested with the baseline series, sometimes with additional series, and the topical medication used along with the ingredients. The relevant data were extracted from our electronic databases developed in-house. RESULTS: Forty-four patients (9%) out of 473 patients suffering from lesions in the (peri)anal/genital area had positive patch test results to topical drug preparations and/or their ingredients, sometimes in association with cosmetics for intimate hygiene. The most frequent sensitizing active principles were local anaesthetics and corticosteroids, while wool alcohols and to a minor extent benzoic acid were the most frequent culprits among the vehicle components and preservative agents, respectively. CONCLUSIONS: The local conditions (eg, occlusion, sweating, moist) in the anogenital area may favour skin sensitization to topical medication used to treat various skin diseases.

Evolution of methylisothiazolinone sensitization: A Belgian multicentric study from 2014 to 2019.

BACKGROUND: In the 2010s an epidemic of allergic contact dermatitis to methylisothiazolinone (MI) occurred in Europe. European authorities banned the use of methylisothiazolinone in leave-on cosmetics in 2017 and limited its use in rinse-off products in 2018. OBJECTIVES: To investigate the sensitization rate to MI in Belgium between January 2014 and December 2019, and to assess cosensitizations to octylisothiazolinone (OIT) and benzisothiazolinone (BIT) in MI-sensitized patients. METHODS: A retrospective study of patch test results with MI, OIT, and BIT observed in patients attending five Belgian hospitals. RESULTS: Overall, 560 of 10 029 patients (5.58%) had a positive patch test reaction to MI, and its sensitization rate decreased from 7.9% in 2014 to 3.1% in 2019. Rinse-off cosmetics, paints, and detergents were the most prevalent sensitization sources in recent years. Simultaneous reactions readily occurred to OIT, and, surprisingly, and increasingly, also to BIT. CONCLUSIONS: Contact allergy to MI in Belgium has reached a pre-epidemic level, reflecting the impact of recent regulatory measures. Leave-on cosmetics, in contrast to rinse-off products, have almost disappeared as sensitization sources in Europe. Paints and detergents also remain problematic. The remarkably high number of patients (co)sensitized to BIT should be a focus of future research.

The presence of benzophenone in sunscreens and cosmetics containing the organic UV filter octocrylene: A laboratory study.

BACKGROUND: The reason why patients photosensitized to the drug ketoprofen (KP) may develop severe photoallergic skin reactions to octocrylene (OCT), an organic ultraviolet filter in sunscreens and cosmetics, remains largely unknown. OCT can be synthesized by using unsubstituted benzophenone (BP), a possible human carcinogen. OBJECTIVES: To verify if, and to what extent, BP residues are present in OCT-containing consumer products. METHODS: The raw material of OCT and 39 skincare products, of which 28 contain OCT, were chemically analysed for the presence of BP by means of liquid chromatography. RESULTS: In the OCT raw material and in all 28 OCT-containing products the presence of BP could be demonstrated, mostly in concentrations above 10 ppm (0.001%), whereas a majority of OCT-free products (8/11, 73%) did not contain BP. Moreover, BP concentrations significantly increased, in a time- and temperature-dependent manner, likely due to the additional degradation of OCT. CONCLUSIONS: Photoallergic contact dermatitis from OCT in patients photosensitized to KP might rely on residual BP impurities. Toxicological and ecological studies that evaluate the safety of OCT might also need to consider the concomitant presence of BP.

Occupational allergic contact dermatitis from systemic drugs.

BACKGROUND: Health-care workers (HCWs) and professionals working in the pharmaceutical industry are at risk of developing occupational allergic contact dermatitis (OACD) from systemic drugs (or drug intermediates). OBJECTIVES: To study demographic characteristics and identify systemic drugs responsible for OACD in patients investigated for contact allergy during the period 2001-2019. METHODS: In the study period, 9780 patients were patch tested with the European baseline series, sometimes with additional series, and other relevant potential allergens. All patients with a positive patch-test reaction to systemic medication exposed to at work were included for further analysis. RESULTS: Of 1248 HCWs examined in our clinic, 201 suffered from OACD. In 26 (13%) dermatitis was caused by skin contact with a systemic drug: 19 nurses, five chemists working in the pharmaceutical industry, one physician, and one veterinarian. In total, 45 positive patch-test reactions to 20 different systemic drugs were found, with tetrazepam (n = 11), ranitidine hydrochloride (n = 5), and zolpidem (n = 4) being the most frequent. Three pharmaceutical chemists were sensitized to a drug intermediate. The lesions were mostly localized on the hands, but often also on the face, as airborne dermatitis. CONCLUSION: As much as 13% of OACD in HCWs, diagnosed in our tertiary referral center, was attributable to systemic drugs, most frequently in nurses.

Topical Corticosteroid Phobia Among Healthcare Professionals Using the TOPICOP Score.

Corticophobia is a major problem in adherence to therapy. This study examined corticophobia among healthcare professionals using the Topical Corticosteroid Phobia (TOPICOP) questionnaire. The TOPICOP questionnaire was adapted for use with professionals (TOPICOP-P). Four groups of professionals: pharmacists, paediatricians, general practitioners and dermatologists were observed. The mean global TOPICOP score was 41.9 ± 14.9%. Pharmacists had the highest scores for corticophobia: a global score of 48.5 ± 13.9%, followed by general practitioners, 46.0 ± 13.5%, paediatricians 39.7 ± 14.5%, and dermatologists 32.3 ± 12.1%. Overall, there was a statistically significant difference in the mean score between the 4 groups (p < 0.05). In conclusion, there is prominent corticophobia among healthcare professionals, especially among pharmacists and general practitioners, which is probably based on insufficient knowledge of topical corticosteroids. In order to improve patient compliance, re-education of healthcare providers is suggested.

Adding sorbitan sesquioleate to the European baseline series: Necessary, reasonable, or unavoidable?

Positive reactions to fragrance mix I (FM I) are frequent in consecutively patch tested patients suspected of having allergic contact dermatitis. However, the FM I test preparations contain 5% of the emulsifier sorbitan sesquioleate (SSO), and it is well known that SSO can cause contact allergic reactions in its own right. Indeed, the available data show that some patients with contact allergy to SSO react to FM I but are not allergic to fragrances. When SSO is not tested, this situation may go unnoticed, a wrong diagnosis of fragrance allergy may be given to the patient, and unjustified advice to avoid fragrances and fragranced products will be given in such cases. To avoid such suboptimal patient care, we postulate that testing with SSO in all patch tested individuals is mandatory. As it is well known that only a minority of FM I-reactive patients will undergo a breakdown test with the ingredients and SSO, testing with SSO in all patients can only be achieved by adding it to the European baseline series. Not testing with SSO may also result in misinterpretation of patch test reactions to Myroxylon pereirae resin and 2-hydroxyethyl methacrylate in the baseline series, as both (may) contain SSO, and, for the same reason, of reactions to several other hapten test materials.

Allergic contact dermatitis caused by topical ophthalmic medications: Keep an eye on it!

BACKGROUND: Allergic contact dermatitis (ACD) caused by topical ophthalmic medications is often overlooked. OBJECTIVES: To study the demographic characteristics, lesion locations and associated medical conditions of the patients with ACD caused by ophthalmic drugs, and to identify the most common allergenic culprits, as well as trends in frequencies over the years. METHODS: From January 1990 until December 2016, 16 065 patients were investigated in our clinic; all patients with a positive patch test reaction to an eye medication or its ingredient(s) having caused ACD were assessed. For each allergen identified, the number of positive test results as compared with the total number of those in the total population, as well as trends across three periods, namely 1990 to 1998, 1999 to 2007, and 2008 to 2016, were studied. RESULTS: One hundred and eighteen patients (0.7%) presented with positive patch test reactions to ingredients of and/or topical ophthalmic medications. Aminoglycoside antibiotics, followed by corticosteroids, as pharmacologically active ingredients, as well as wool alcohols, thiomersal, and benzalkonium chloride, as excipients, were the most frequent culprits. Chloramphenicol showed a decreasing trend of positive reactions over time, whereas reactions to tobramycin increased. CONCLUSION: ACD caused by eye medication is mainly attributable to active principles, but other excipient ingredients, beside the products "as is," should be tested as well.

Concomitant contact-allergic reactions to iodopropynyl butylcarbamate and iodine.

BACKGROUND: Iodopropynyl butylcarbamate (IPBC) is a broad-spectrum preservative for use in several product types, including cosmetics, in which its concentrations have been limited by EU legislation because of concerns related to its iodine content and release, and the risk of subsequent iodine overdose. OBJECTIVES: To report on concomitant patch test reactions observed with iodine and IPBC in patients sensitized to iodine-containing antiseptics. PATIENTS: Between 2012 and 2018, seven patients, six from Belgium and one from France, two suffering from acute dermatitis during surgical interventions, four from dermatitis caused by wound treatment, and one from occupational dermatitis, were shown to be sensitized to iodine and/or povidone-iodine (PVP-I), which was considered to be relevant for their dermatitis. All patients were coincidentally also patch tested with IPBC. RESULTS: All patients showed positive patch test reactions to several other allergens, including IPBC. No relevance could be detected for IPBC. CONCLUSIONS: We suspect that, notwithstanding the absence of firm evidence for IPBC being dehalogenated to produce free iodine in animals or in humans, the patch test reactions to IPBC in iodine-allergic subjects were possibly caused by free iodine released from this preservative agent, thus underlining the EU restrictions regarding the use of this preservative in cosmetics.

Allergic contact dermatitis caused by calcipotriol.

BACKGROUND: Calcipotriol, a synthetic vitamin D analogue, is widely used for the topical treatment of psoriasis. It often causes irritant reactions, whereas allergic contact dermatitis has less commonly been reported. OBJECTIVES: To report on 6 patients (among them an 11-year-old child) who presented with eczematous lesions complicating pre-existing dermatitis, observed in our tertiary referral patch test clinic between 2004 and 2016. METHODS: Patch tests were performed with the commercial preparation used by the patients and/or its ingredients, including calcipotriol (2 or 10 µg/ml in isopropyl alcohol), according to ESCD patch test guidelines. RESULTS: Allergic contact dermatitis was confirmed in all cases, and the lesions improved following treatment with topical corticosteroids and/or oral medication. CONCLUSIONS: When topical treatment with calcipotriol fails to improve, or even worsens, existing skin lesions, contact allergy should be suspected. A patch test concentration of 2 µg/ml in isopropyl alcohol seems to be the most suitable. According to the literature, patients sensitized to calcipotriol may tolerate topical therapy with other vitamin D3 analogues, particularly tacalcitol.

Allergic contact dermatitis caused by topical herbal remedies: importance of patch testing with the patients' own products.

BACKGROUND: Natural ingredients have variable compositions, so their allergenic potencies may differ. OBJECTIVES: To retrospectively analyse subjects reacting to herbal remedies over the past 27 years, with the aim of (i) evaluating demographic characteristics and lesion locations, (ii) describing the frequencies of positive patch test reactions, (iii) identifing sensitization sources, and (iv) studying concomitant sensitivity. PATIENTS AND METHODS: In total, 15980 patients were patch tested between 1990 and 2016 with the European baseline series and/or other series, product(s) used, and, whenever possible, the respective ingredients. RESULTS: Altogether, 8942 (56%) of 15 980 patients presented with at least one positive reaction. Reactions to topical herbal medicines, most often applied to treat an eczematous condition, leg ulcers, or other wounds, were seen in 125 (0.8%), that is, 1.4% of the contact-allergic subjects. Hands, legs and feet were the most frequently affected body sites. Twenty-one botanical allergens were identified, the commonest being Myroxylon pereirae (balsam of Peru), Compositae plants, and tincture of benzoin. Many patients presented with multiple positive test reactions, and some did not react to the commercial allergens but only to the products used. CONCLUSIONS: Topical herbal remedies should not be applied on damaged skin, as multiple sensitization may develop. Moreover, patch testing with the culprit products is important for the diagnosis.

Allergic contact dermatitis caused by acrylic-based medical dressings and adhesives.

BACKGROUND: Acrylates and methacrylates are acrylic resin monomers that are known to induce skin sensitization as a result of their presence in different materials, such as nail cosmetics, dental materials, printing inks, and adhesives. Allergic contact dermatitis resulting from the use of modern wound dressings containing them has only rarely been reported. OBJECTIVES: To describe 2 patients who developed allergic contact dermatitis caused by acrylic-based modern medical dressings and/or adhesives. METHODS: The medical charts of patients consulting since 1990 were retrospectively reviewed for (meth)acrylate allergy resulting from contact with such materials, and their demographic characteristics and patch test results were analysed. RESULTS: Two patients were observed in 2014 and 2016 who had presented with positive patch test reactions to several acrylic-based dressings and/or adhesive materials, and to several (meth)acrylates, that is, hydroxyethyl acrylate, hydroxyethyl methacrylate, ethyleneglycol dimethacrylate, bisphenol A-glycidyl methacrylate/epoxy-acrylate, urethane diacrylate, and/or penta-erythritol acrylate. CONCLUSIONS: Allergic contact dermatitis needs to be considered in patients with eczematous reactions or delayed healing following the use of acrylic-based modern dressings or adhesives. However, identification of the culprit allergen is hampered by poor cooperation from the producers, so adequate labelling of medical devices is an urgent necessity.

Contact dermatitis caused by a new rubber compound detected in canvas shoes.

BACKGROUND: In 2015 and 2016, female patients in Flanders consulted a dermatologist because they developed skin lesions after wearing a specific brand of canvas shoes. OBJECTIVES: To identify the culprit allergen in the shoes. METHODS: Eighteen young females aged 14-22 years presented with itching and erythematous to purple-coloured eczematous lesions on both feet. They were patch tested by 10 dermatologists with the European baseline series. Some patients underwent testing with additional series. Pieces of the shoe fabrics were tested in 11 of 18 patients. Chemical analysis of the shoe materials was performed. Finally, patients were tested with a thin-layer chromatogram of the shoe extracts and dilutions of the suspected rubber compound. RESULTS: All 18 patients showed positive reactions to thiuram mix. Ten of 11 patients reacted to a piece of shoe fabric. Chemical analysis showed the presence of dimethylthiocarbamylbenzothiazole sulfide (DMTBS). No thiurams were detected. Four patients tested with the chromatogram developed positive reactions to DMTBS. Positive reactions to low concentrations were observed in the 4 patients tested with a DMTBS dilution series; one patient reacted to 0.00001% in acetone. CONCLUSIONS: DMTBS, the culprit allergen, is a component formed during rubber vulcanization that probably cross-reacts with the thiuram mix.

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

BACKGROUND: Allergic contact dermatitis is the most common adverse reaction caused by topical drugs. OBJECTIVES: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Allergic contact dermatitis caused by cocamide diethanolamine.

BACKGROUND: Cocamide DEA (CAS no. 68603-42-9) is a non-ionic surfactant frequently used in industrial, household and cosmetic products for its foam-producing and stabilizing properties. Contact allergy has been reported quite rarely in the past, but recently several cases were published, raising the question of an increase in the frequency of allergic dermatitis caused by this substance. OBJECTIVES: To describe cocamide DEA-allergic patients and their characteristics observed in our department. METHODS: Medical charts of patients, investigated between 1990 and December 2015, were retrospectively reviewed for cocamide DEA-allergy. Demographic characteristics and patch test results were analyzed. RESULTS: Out of 1767 patients tested, 18 (1%) presented with an allergic reaction to cocamide DEA, all of them at least with hand dermatitis. Twelve patients had (past) occupational exposure to cocamide DEA. Out of the 18 patients, 15 showed (most often) multiple positive reactions and 7 also suffered from atopic dermatitis. CONCLUSIONS: Cocamide DEA allergy is relatively rare, despite frequent use, and an increasing trend was not observed. Reactions to cocamidopropyl betaine and cocamide MEA only occurred in some of the subjects tested. Shampoos and liquid hand soaps/cleansers dominated as sources of exposure. All patients presented with an impaired skin barrier due to atopic and/or previous contact dermatitis.