Two Cases of Allergic Contact Dermatitis Caused by Coco Betaine in Clobetasol Propionate Shampoo

Diagnosis of allergic contact dermatitis to epoxy can be challenging especially in the occupational context. We present a second case of allergic contact dermatitis (ACD) to benzyl alcohol in an epoxy floor paint.1 A 45-year-old Caucasian male with a past history of psoriasis was referred for hand and wrist eczema. (Figure 1). He had been working in industrial paving for 20 years. In his work he used several products such as cement, sealants and epoxy floor paints. His eczema was considerably worsened at work and improved on holidays. Patch tests were performed with the European Baseline Series and cosmetic, rubber, plastic/glue, epoxy and acrylates series using test preparations from SmartPractice Europe, (Greven, Germany), using IQ ultra chambers® from Chemotechnique MB Diagnostics AB (Vellinge, Sweden) according to ESCD guidelines with an occlusion time of 48 h. We routinely patch test benzyl alcohol along with baseline series as additional GERDA series (french group of dermato-allergology study and research). Positive results were found for benzyl alcohol 10% in softisan 649 (++), diglycidyl ether of bisphenol A (DGEBA) 1% pet (++), 1,6 hexanediol diglycidyl ether 0.25% pet (++), 1,4 butanediol diglycidyl ether 0.25% pet (++), diaminodiphenylméthane 0.5% pet (++) at D3 and D10 (Table 1). A second series of patch tests were performed to isocyanate series which remained negative. The safety data sheets of the floor paints used at work, clearly mentioned the presence of benzyl alcohol in various products confirming current definite relevance of this test. (Table 1). He was advised to avoid the exposure to these products at his workplace, and his hand dermatitis considerably improved. Benzyl alcohol (CAS no. 100-51-6) is a well-known allergen in antiseptic products. Multiple cases of sensitizations in antiseptics have been described by the French network REVIDAL-GERDA.2 It can also be used as a fragrance component, preservative, solvent, food additive and excipient in medicinal products.3 Its presence is not so well known in the construction sector, particularly in epoxy systems. It is generally used as a thinner in epoxy resins (an additive to regulate viscosity) and can be found in the epoxy resin part (A) or the hardening part (B). Benzyl alcohol was not present in any of the patient's personal cosmetic products. The patient's work related eczema could be explained by ACD to benzyl alcohol as well as ACD to several other epoxy compounds. Occupational ACD to benzyl alcohol in epoxy systems has recently been reported in another patient working with similar products for the repair and coating of concrete floors.1 Regular occupational exposure to epoxy products with benzyl alcohol, with an altered skin barrier could explain the sensitization to this allergen. Furthermore, a positive patch test reaction to diaminodiphenylmethane (MDA) may indicate ACD to isocyanates. The safety data sheet of one of his products, a polyurethane sealant, mentioned the presence of diisocyanate de 4,4′ methylenediphenyle, but it was not tested and our patient had negative isocyanate series (with toluene 2,4 diisocyanate [TDI] 2%, diphenylmethane 4,4′ diisocyanate [MDI] 0.5%, isophorone diisocyanate [IPDI] 1%, hexamethylene diisocyanate [HDI] 0.1% and polymeric diphenylmethane diisocyanate [PDMI] 2%). A positive reaction to MDA could also indicate ACD to hydrogenated formaldehyde-benzamine polymer (FBAP, CAS no. 135108-88-2) as described by Suomela, due to structural resemblance or a possible cross allergy.4 The safety data sheet of one of our patient's epoxy products mentioned the presence FBAP, as well as BA, but we could not test it separately to confirm this allergy. In conclusion, this is the second case of hand ACD associated with benzyl alcohol in an epoxy system, and can be considered an emerging allergen of relevance in occupational ACD to epoxy system in the construction sector. Marion Menanteau: Investigation; writing – original draft; writing – review and editing. Lynda Bensefa-Colas: Writing – review and editing. Marie-Noëlle Crepy: Writing – review and editing; supervision. We thank Sylvain Caillol PhD Research Director, CNRS (National Centre for Scientific Research) for his contribution to the discussion. The authors declare that they do not have any conflicts of interest regarding this study. The patient in this manuscript has given informed consent to publication of their case details and photographs.

Hydroxyacetophenone (CAS 99–93-4) is a phenolic compound found in Norway spruce and widely used in cosmetics for its antioxidant properties [1]. This report adds two more cases linked to cosmetic products containing hydroxyacetophenone. Oral informed consent was obtained from the patients for the publication of their images and clinical details. A 63-year-old male, with a history of psoriasis, attended for a follow-up consultation. His topical treatment was adjusted to include a psoriasis-specific emollient cream (XEMOSE PSO, Uriage) and topical steroids. Seven days later, the patient developed eczematous plaques on the flanks, buttocks, and eyelids (Figure 1A). A skin biopsy showed eczematous dermatitis with no abnormalities on direct immunofluorescence. The repeated application test (ROAT) was positive for XEMOSE PSO. Patch-tests (Chemotechnique Diagnostics, Vellinge, Sweden) with the ingredients of the emollient cream confirmed a strong positivity (++) for hydroxyacetophenone provided by the manufacturer (0,6% aq) at D2 and D4 (Figure 1B). Discontinuation of the implicated products and local treatments led to a gradual improvement of the eczema. A 66-year-old female presented with a 6-month history of periorbital edema of the lower lid and facial eczema (Figure 2A). She reported the daily use of an anti-wrinkle day cream (Crème Riche, Yves Rocher, France), a night cream (Cien Q10, Lidl), a serum, and sunscreen. Patch-testing was performed using the European Baseline Series, the additional allergens from the GERDA series, and the specific products used by the patient. The patient had strong positive reactions (++) at D4 to both anti-wrinkle creams and to hydroxyacetophenone (0,6% aq), a common ingredient to both (Figure 2B). A mild response (+) was already observed at D2 Hydroxyacetophenone is not widely recognised as a contact allergen. Nonetheless, three cases of contact dermatitis associated with this compound and one case of photo-aggravated allergic contact dermatitis have been documented. The first case involved occupational eczema in a paper mill worker exposed to a myxobactericide containing 2-bromo-4′-hydroxyacetophenone. Patch testing confirmed sensitization to hydroxyacetophenone [2]. In the second case, a woman developed pruritic facial dermatitis following the use of a cosmetic cream containing hydroxyacetophenone, with patch testing confirming the allergic reaction and resolution upon discontinuation of the product [3]. Similarly, the third case described facial eczema in a patient using an anti-wrinkle serum, with hydroxyacetophenone identified as the sensitising agent through patch testing [4]. More recently, Pesqué et al. described a case of corticosteroid-resistant facial and cervical eczema associated with the use of a sunscreen containing hydroxyacetophenone. Patch testing with hydroxyacetophenone (0.6% aq) resulted in a mild (+) reaction, while photopatch testing produced a stronger (++) response. This case highlights the need to consider hydroxyacetophenone as a potential photoallergen [5]. To date, no standardised concentration for patch testing hydroxyacetophenone has been established. Nevertheless, testing at 0.6% in water appears sufficient to detect sensitization. Additionally, several cases of allergic contact dermatitis related to resacetophenone, a compound used in nail antifungal preparations, have been documented. However, the potential for cross-reactivity between hydroxyacetophenone and resacetophenone remains unknown [6-8]. We present two new cases of contact dermatitis caused by hydroxyacetophenone, a widely used preservative in cosmetics and industrial products. These findings suggest that hydroxyacetophenone should be considered as a potential allergen in individuals presenting with contact dermatitis, especially in those using cosmetic formulations containing this preservative. Samia Leghlam: writing – original draft. Evelyne Collet: supervision. Louise Collin: supervision. Camille Leleu: writing – review and editing. Open access publication funding provided by COUPERIN CY26. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.

Basic Blue 99 (CAS no. 68123–13-7) is a type of dye contained in hair colour treatment products. While there have been reports of immediate-type allergies, reports of contact dermatitis are few. In Japan, there is a high need for hair dyes that colour hair black. Hair colour treatment products have become widely used by patients with allergic contact dermatitis to substances like paraphenylenediamine, or by those wishing to avoid such reactions. It is a troublesome issue when contact allergies occur from hair colour treatment products used to avoid allergies. We report five cases of allergic contact dermatitis caused by Basic Blue 99 contained in hair colour treatment products that we encountered over a recent 3-year and 3-month period from March 2021 to June 2024. For patch testing, Finn Chambers® on Scanpor tape® were used; occlusive exposure was for 48 h. Conforming with ICDRG standards, readings were performed on Day (D) 2, D3 and D7 or D8. We used Basic Blue 99 1% pet obtained from the company marketing the hair colour. We also included the participants' own semi-permanent hair dye as used by them in terms of open tests. The cases involved one male and four females aged 51–81 years, all of whom developed eczema on the head after using hair colour treatment products. In two cases, the condition was also observed on the face, and in one case, on the trunk. Patch tests with 1% Basic Blue 99 showed positive reactions of + to ++ according to ICDRG criteria in all five cases. Open tests with the hair colour treatment products used were also positive in four cases. Among these, three cases were positive to paraphenylenediamine, and two cases were positive to p-methylaminophenol sulphate (Table 1). Basic Blue 99 has been in production since 19911 and is used in hair colour treatment products at concentrations of 0.004%–2%.2 it is an impure direct dye mixture (a mixture of 23–32 substances at various concentrations and with varying composition) in temporary or semi-permanent hair dye formulations, with a maximum on-head concentration of 1.0% (Scientific Committee on Consumer Safety [SCCS] Opinion on Basic Blue 99 [CO59]-SCCS/1585/17-Final Version, June 2017). Because of the complex and batch-variable composition, the SCCS could not conclude on its safety, not even up to a 1% concentration on-head (lower than the concentration allowed in other parts of the world). Regarding the sensitization potential of Basic Blue 99, Søsted et al.3 examined the predicted sensitization values of 229 hair colouring-related substances and reported that Basic Blue 99 has an equal or higher potential than paraphenylenediamine. While this result is based on predictions from chemical structure and may differ from actual biological reactions, it suggests that Basic Blue 99 cannot be considered safe. While there have been reports of immediate-type allergies,1, 4-6 reports of contact allergies to Basic Blue 99 are few.7-9 In the report by De Groot A C et al.,7 1% Basic Blue 99 was used for patch testing, and it was reported to be negative in 25 healthy control subjects. Iwasaki et al.9 reported a case of severe allergic contact dermatitis accompanied by fever and mucosal symptoms. The five cases reported here did not show symptoms of immediate-type allergy or systemic symptoms. Of the five cases reported here, four had a history of contact dermatitis from oxidative hair dyes, and many showed positive patch test results to allergens other than Basic Blue 99. As consumers become more aware of the risk of contact allergies from oxidative hair dyes, the market for alternative colour treatment products may expand, potentially increasing the number of patients. It will be necessary to add Basic Blue 99 as one of the patch test allergen for hairdressing series, and to further clarify which of the mixed components is the responsible allergen. Kazue Nishioka: Conceptualization; investigation; writing – original draft. Akiko Koizumi: Investigation. Yuko Takita: Investigation. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author (Kazue Nishioka) upon reasonable request.

Olanedine solution is a new antiseptic, and several cases of allergic contact dermatitis caused by the agent were reported in 2018; however, these cases were diagnosed based on positive results in 2-day closed patch testing of Olanedine solution "as is." To present another case of Olanedine-induced allergic contact dermatitis and to analyze the optimal patch-testing method for this condition. A 34-year-old Japanese female patient and 25 healthy control subjects were patch tested using wet filter paper, which had been treated with 15 μL Olanedine solution, and dried filter paper, which had been treated with 15 μL Olanedine solution and then dried. The patient and all of the control subjects exhibited false-positive reactions due to irritation in the 2-day closed patch tests with wet filter paper containing Olanedine solution "as is." The tests with dried filter paper produced a positive reaction on day 7 in the patient, and negative reactions in all control subjects. It is preferable to perform 2-day closed patch tests using filter paper with the test solution "as is," which had been dried before application in order to correctly diagnose antiseptic-induced allergic contact dermatitis.

We report the first two cases of allergic contact dermatitis from resacetophenone in a nail antifungal preparation. Patch tests gave positive reactions to resacetophenone (0.1% and 1% pet.). No cross-reactions with resorcinol or phenylethyl resorcinol were found. Patch testing with individual ingredients is paramount to diagnose new allergens.

Alergia de contacto a 3-dimetilaminopopilamina y cocamidopropil betaína

Benzoisothiazolinone (BIT) is one of the isothiazolinone derivatives which is widely used in household detergents, industrial products, cosmetic products, paints, adhesives, papers and in textile industry. Other isothiazolinone derivatives include methylchloroisothiazolinone (MCI), methylisothiazolinone (MI) and octylisothiazolinone (OIT), which may be present in laundry detergents.1 BIT and OIT are not permitted in EU cosmetic products. Cases of allergic contact dermatitis to laundry detergent have been reported in a 7-year-old girl who tested positive for MCI/MI with truncal dermatitis from clothing and a non-atopic factory worker involved in detergent production who tested positive for MCI/MI and MI with hand and pretibial dermatitis.2 We report a case of a 74-year-old non-atopic man who was referred to the dermatology department with a pruritic eruption affecting the legs, back, chest and inner thighs, sparing the genital area, for the last 8 years. There was an initial suggestion of a drug eruption due to rivaroxaban or bisoprolol, which had been started 3 weeks prior to the onset of the rash. The rash persisted despite changes in his medication. He had also changed his sofa twice, which made no difference. He plays guitar in a band. Multiple skin biopsies had been taken over the years, which had shown spongiotic and non-specific inflammation. On examination, there were ill-defined erythematous scaly patches on the torso and limbs, sparing the face, hands and feet. He was treated with various potency topical corticosteroids with minimal improvement. He could not tolerate azathioprine and declined further immunosuppressants. He was patch tested to the British Society for Cutaneous Allergy baseline series, cosmetic and fragrance series under occlusion with IQ Ultra chambers (Chemotechnique Diagnostics, Vellinge, Sweden) for 48 h. Patch test readings were conducted on Day 2 and Day 4, respectively, where he was positive for nickel + on Day 2 and ++ on Day 4. BIT was ++ on Day 4 only. Patient information leaflets for the relevant allergens were given to the patient. He returned 2 months later with complete clearance of his rash. He had found BIT in his Aldi laundry detergent. His skin had vastly improved with the switch to a different laundry product. There have been limited published reports of laundry detergents causing allergic contact dermatitis since the early 1970s when there were multiple reports highlighting optical brighteners and enzymes in laundry detergents causing allergic contact dermatitis.3 Ten common allergens in textile manufacturing and laundering products were reported to be benzisothiazolinone, benzyl benzoate, cocamidopropyl betaine, decyl glucoside, fragrances, lauryl glucoside, MI, MCI, phenoxyethanol and propylene glycol.4 Allergic contact dermatitis due to MI in laundry detergent has been previously reported,5 but in our case, testing to MI, 0.2% aq and MCI and MI 0.02% aq were negative. Although patient suspicion of their laundry detergent as a cause of dermatitis is high, a clear causal relationship between a detergent and the occurrence of dermatitis is often difficult to establish. BIT is a borderline irritant patch test material, and hence, uncertain patch test reactions are frequent. However, in this case there was rapid and complete clearance of long-standing intractable dermatitis on avoidance of BIT in laundry detergents. In the case of a clear-cut positive patch test reaction to BIT with no other identified source, patients should be advised to obtain information on the ingredients of their laundry detergent. From our patient's experience, benzisothiazolinone free laundry detergents are quite challenging to find. A study was done to analyse the concentrations of isothiazolinones in clothes after machine washing. The results revealed negligible isothiazolinone concentrations independent of the type of machine wash or material but showed the highest concentration of isothiazolinones in the control hand washing group.6 To our best knowledge, this is the first-ever reported case of allergic contact dermatitis to BIT containing laundry liquid with complete clearance of his dermatitis by the avoidance of such product. Mun Wai Lam: Writing – original draft; resources. Tang Ngee Shim: Writing – review and editing; supervision. The authors declare no conflict of interest.

Recently, many cases of acrylate-associated allergic contact dermatitis have appeared among nail salon workers. Common acrylate-containing products in nail salons include traditional nail polish, ultraviolet-cured shellac nail polish, ultraviolet-cured gel nails, and press-on acrylic nails. Nail salon technicians seen in the occupational medicine clinic in 2015 and 2016 were identified, and their patch test results and clinical features were summarized. Patch testing was done with the Chemotechnique (Meth)Acrylate nail series, and either the North American Standard series or the North American Contact Dermatitis Group screening series. Six patients were identified, all women, ages 38 to 58. Common presentations included erythematous dermatitis of the dorsa of the hands, palms, and forearms and fissures on the fingertips. Less common sites of eruptions included the periorbital region, cheeks, posterior ears, neck, sacral area, lateral thighs, and dorsa of the feet. All patients reacted to hydroxyethyl methacrylate, and 5 patients reacted to ethyl acrylate. Each patient also reacted to (meth)acrylates that are not found on either standard series, including ethyleneglycol dimethacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxyethyl acrylate. The authors report 6 cases of allergic contact dermatitis to acrylates in nail technicians seen over the past year, representing a new trend in their clinic. These cases are reflective of a growing trend of nail technicians with allergic contact dermatitis associated with occupational (meth)acrylate exposure. Efforts to improve prevention are needed.

BACKGROUND AND OBJECTIVESContact allergy is associated with a significant morbidity all over the world. This study was performed to investigate the pattern of sensitization by contact allergens in the local population.DESIGN AND SETTINGRetrospective study to investigate patch test reactivity among patients with clinical diagnosis of contact dermatitis who were referred to the allergy clinic at the King Khalid University Hospital, Riyadh, between April 2008 and March 2010.PATIENTS AND METHODSOf the 196 patients referred to the allergy clinic over the 2-year period, 91 (46.4%) patients reacted to one or more patch test allergens, and these patients were included in this study. The study group included 82 (91.1%) of Saudi nationality and 9 (8.9%) patients of other nationalities. The patch test was performed using the T.R.U.E TEST, containing 24 allergens/allergen mixes.RESULTSOf the 91 cases who reacted positively to one or more allergens, 67 (73.6%) were females with a mean age of 37 (8.3 years) and 24 (26.4%) were males with a mean age of 34 (11.6 years). Thirty-three (36.2%) patients reacted to nickel sulfate, 14 (15.3%) to p-phenylenediamine, 13 (14.2%) to p-tert-butylphenol-formaldehyde resin, 13 (14.2%) to thimerosal, and 9 (9.8%) to colophony. Reactivity against the rest of the allergens was not remarkable. A significantly higher percentage of females reacted to nickel sulfate (84.8% vs 15.2% in males; P=.0001), p-tert-butylphenol-formaldehyde resin (92.3% vs 7.7%; P=.0001), and thimerosal (76.9% vs 23.1%; P=.03).CONCLUSIONSPatch test reactivity to nickel sulfate was high. The pattern of contact allergy observed in this study indicates the need for large-scale investigations to identify local allergens responsible for contact allergy and for formulation of policies directed towards avoidance of exposure.

Cocamidopropyl betaine (CAPB) is an amphoteric surfactant. It has several functions, including producing effervescence and washing effects, and thus, it is used in many cleansing products, such as shampoo and liquid body cleansers. Recently, it has become clear that some impurities that arise during the manufacturing process can have sensitizing effects. Herein, we report a case of allergic contact dermatitis caused by detergents containing CAPB, in which an impurity was determined to be the possible causative agent by patch testing and chemical analysis.A 64-year-old Japanese female developed a skin rash on the hairlines of her forehead and nuchal region one month before her first visit to our clinic. Later, the rashes, which were composed of desquamative erythema, expanded to her face, neck, upper back, and chest. Patch tests produced positive results for a shampoo and liquid body cleanser (1% aq.) that she had used as well as for CAPB (1% aq.); lauramidopropyl betaine (LAPB) (1% aq.); and lauramidopropyl dimethylamine (LAPDMA) (0.05% aq.), which is an impurity of CAPB. The rashes resolved completely after we instructed her to use products without CAPB and LAPB. When issuing such instructions, clinicians should have correct knowledge about surfactants, such as the differences between cosmetic ingredient names and quasi-drug ingredient names.

1,3-Butylene glycol (1,3-BG) is widely used in cosmetics, including low-irritant skin care products and topical medicaments, as an excellent and low-irritation humectant. We report a case of allergic contact dermatitis caused by 1,3-BG. A 28-year-old woman suffered from an itchy erythematous eruption on her face. By 2days of closed patch testing, her own cosmetics and many of the hypo-irritant skin care products showed positive results. A second patch testing showed positive reaction to 1,3-BG (1% and 5%). 1,3-BG was a common component in most of the products that had elicited a positive reaction in the first patch testing. Although allergic contact dermatitis due to 1,3-BG is not so common, we have to consider 1,3-BG as a possible contact allergen in the patients presenting with allergic contact dermatitis due to various cosmetics.

Alfa-lipoic acid (α-LA), also known as 1,2-dithiolane-3-pentanoic acid or 6,8-thioctic acid (CAS number 1077-28-7), is a pale-yellow crystalline powder with antioxidant properties. Despite its large use in cosmetics and topical products, few reports are found in the literature concerning its sensitizing potential.1-3 A 86-year-old woman presented with an acute dermatitis of her lower limbs. Prior to this, the patient suffered from chronic leg venous insufficiency for which she was advised to use Tiobec® cream (produced by Laborest, Milan, Italy), containing α-LA at 5% concentration, by the Pharmacist. The dermatitis developed after she began the topical use of the product. Tiobec® cream is an over-the-counter topical product typically used for cutaneous inflammation, dermatitis and for post-surgical scar care due to its antioxidant, anti-inflammatory and emollient properties. The patient showed a severe itching erythematous, oozing dermatitis of her lower legs and thighs (Figure 1). The patient was advised to stop the use of the Tiobec® cream and topical and systemic corticosteroids were prescribed. Six months later, the patient was patched-tested with the Società Italiana Dermatologia Allergologica Professionale Ambientale baseline series (SmartPractice, Rome, Italy) and the topical product Tiobec® cream, tested ‘as is’.4 Patch tests were applied on her back and left in occlusion for 2 days, using the AllergEAZE® skin patch test chambers (Smart Practice) on Soffix tape (Artsana, Grandate, Italy). Readings were performed on day (D) 2 and D3, and a positive reaction (+++) at D2 and D3 was observed only to Tiobec® cream. Additional patch tests were performed with its main component, α-LA (ALA 22121 supplied by ACEF SpA, Fiorenzuola d'Arda [PC], Italy). The component α-LA was tested at the 0.5%, 1% and 5% concentrations in petrolatum. All the three concentrations gave a strong positive reaction (+++) at D2 and D3 (Figure 2). The patient declined further patch tests with lower concentrations. Patch tests with α-LA 0.5%, 1% and 5% in petrolatum were successively performed in seven healthy controls, with negative results. α-LA was first isolated in 1951 as part of the enzymatic complex involved in oxidative metabolism. It has antioxidant properties due to its role as inhibitor of the activation of transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells.5 It is also a powerful anti-inflammatory agent, acting as both a free radical scavenger and a modulator of the inflammatory response. This makes it a logical choice for cosmetic and medical industries, mainly in ‘anti-age’ products and for treating various inflammatory dermatitis. Three patients with severe facial dermatitis caused by an ‘anti-age’ cream newly launched in Sweden were reported in 2006. Further testing with all ingredients of the cream demonstrated a clear positivity to α-LA 5% petrolatum in all three patients; serial dilution of the substance gave a positive reaction down to a concentration of 0.025% in two out of three patients.1 A further case of severe facial dermatitis caused an anti-ageing cream containing α-LA and vitamin C was described in Belgium in 2016. Initially, patch tests were performed with the Belgian baseline series and the patient's cosmetic products ‘as is’, including the anti-wrinkle cream, which gave a clear positive reaction; upon further testing with all ingredients of the cream, a strong positivity to α-LA 5% petrolatum was demonstrated.2 Recently, a further case of allergic contact dermatitis caused by α-LA (tested 3% aq.) in eye drops for dry eyes (containing 0.1% α-LA) has been reported.3 In 2015, Rizzi et al. described a case of a pruritic maculopapular rash on the face and scalp after 10 days of treatment with dietary supplement containing α-LA and other oral drugs. Patch tests were performed and gave a strong positive result (+++) at D2 and D3 for the dietary supplement and at D3 for all dilutions of α-LA (0.025% petrolatum, 2.5% petrolatum and 5% petrolatum). Prick tests were also performed but resulted negative.6 To our knowledge, this is the first report of allergic contact dermatitis to α-LA as a constituent of a topical treatment. This case confirms the sensitizing properties of α-LA and underlines the risk of using this molecule especially in areas at high risk of developing contact sensitization such as legs with chronic venous insufficiency or ulcers. Performing patch tests with the patient's own products and their ingredients, may represent the key for identifying unusual relevant allergens. The most appropriate dilution/concentration for α-LA to be used in patch tests deserves more studies. Monica Corazza: Conceptualization; project administration; supervision; validation. Edoardo Arlotti: Conceptualization; data curation; validation; writing – original draft. Natale Schettini: Data curation; investigation; validation. Lucrezia Pacetti: Data curation; validation; writing – original draft. Anna Bianchi: Formal analysis; investigation; resources; validation. Alessandro Borghi: Conceptualization; project administration; supervision; validation. The authors declare no conflicts of interest.

Essential oils are becoming increasingly popular mainly for their fragrance and their perceived homeopathic benefits. They are derived from a highly variable range of botanicals, many of which contain common allergens such as cinnamic aldehyde, limonene or linalool.1, 2 We report an unusual case of allergic contact dermatitis (ACD) following the ingestion of edible essential oils [doTERRA drops (UT, USA)] in a 58-year-old female presenting to the contact dermatitis clinic. She reported a 2-year history of stomatitis with oral ulcers with minimal cheilitis aggravated by various foods including tomatoes (Figure 1). Other relevant medical history includes recurrent hand dermatitis. The patient was patch tested to the Australian Baseline Series, cosmetics common, fragrance common, cheilitis common, toothpaste and bakery series. Additionally the patient was tested to selected allergens from the essential oils series as well as the patient's own products including her doTERRA essential oils ‘as is’. Allergens were obtained from Chemotechnique Diagnostics (Vellinge, Sweden). The allergens were fixed to the skin with AllergEAZE test chambers (SmartPractice, Calgary, Canada) and occluded for 48 h. Readings were performed according to the International Contact Dermatitis Research Group guidelines on Days 2 and 4. Patch test reactions are summarised in Table 1. Positive allergens were contained in almost all ingredients of the patient's essential oil products as shown in Table 2. She also showed positive reactions to lemongrass oil and lavender, likely caused by reactions to limonene and linalool which are contained in them. The patient was advised to avoid all essential oils, fragrance products and products containing cinnamon, spearmint, citrus, lavender and lemongrass. She reported significant improvements in her stomatitis after reducing the use of oral essential oils when reviewed 1 year later. This is a rare case of intraoral ACD caused by fragrance and spice allergens found in edible essential oils. Similar cases have been reported for products containing cinnamon, spearmint oil, anise oil and L-carvone contained in toothpastes or denture cream.5-7 The Information Network of Departments of Dermatology database from 2010 to 2019 found 908 (8.3%) of the 117 279 patients returned at least one positive result to essential oils.8 Concomitant sensitisation to other fragrances and/or essential oils is also common due to the overlap of allergens, making patients vulnerable to becoming polyreactors.8, 9 ACD to essential oils frequently presents as eczematous and vesicobullous lesions in areas of contact.10 A French study investigating ACD to essential oils also reported oral mucosal damage in one of their patients, but they did not have direct oral essential oil intake.10 There were no other reports of stomatitis secondary to direct essential oil use. In conclusion, we report a rare case of allergic contact stomatitis caused by essential oils in a polyreactor to multiple fragrances and spices. Careful consideration of all foodstuffs and fragrant products needs to be taken when investigating the cause of recurrent stomatitis. A formal written consent has been obtained from the patient regarding the use of a photograph which may show them in a recognisable fashion in this publication. Sangho Lee: Writing – original draft; data curation; visualization. Kajal Patel: Conceptualization; data curation; supervision; writing – review and editing. Bruce Tate: Supervision; conceptualization; writing – review and editing; validation. The authors declare no conflicts of interest.

Three cases of allergic contact dermatitis from anaerobic acrylic sealants (all from Loctite products) and seven cases of allergic acrylate contact dermatitis from dental composite resins have been detected. The different types of acrylate patch test reactions are described.

Hydroxyphenyl propamidobenzoic acid (HPPBA; syn. dihydroavenanthramide D) is a synthetic analogue of naturally occurring avenanthramide which can be found in oats.1 Symcalmin is a 5% solution of HPPBA in a vehicle of (1:1) butylene glycol and pentylene glycol and is commonly used by the pharmaceutical and cosmetic industry for its anti-inflammatory and anti-oxidant (i.e., anti-irritant and anti-itch) properties.2-4 We report the first case of allergic contact dermatitis (ACD) likely caused by HPPBA. A 29-year-old Caucasian female, with no relevant medical history, presented with a generalized eczema evolving for 1 week. The rash had initially appeared on her left forearm and had secondarily spread to the trunk and limbs (Figure 1A–C). Three weeks earlier, she had been diagnosed with a left-handed De Quervain's tenosynovitis, for which she had applied an etofenamate-containing gel (Traumalix DOLO gel 5%, Drossapharm SA, Basel, Switzerland) and a Symcalmin-containing wound-healing cream (Bepanthen Sensiderm, Bayer AG, Leverkusen, Germany). Patch tests were performed with the European baseline, cosmetic, preservative and excipient series (Chemotechnique Diagnostics, Vellinge, Sweden, and AllergEAZE, Calgary, Canada), and with the patient's own products (patch-tested “as is”). All tests were mounted on IQ Ultra chambers (Chemotechnique Diagnostics), fixed with Mefix (Mölnlycke Health Care, Gothenburg, Sweden) and occluded for 48 h. Readings, performed on day (D) 2 and D4 according to International Contact Dermatitis Research Group criteria, showed a positive reaction to Traumalix DOLO gel 5% (D2++, D4+++) and Bepanthen Sensiderm (D2−−, D4++) (Figure 1D). Further patch-testing confirmed contact allergy to etofenamate 2% pet (Chemotechnique Diagnostics), the active ingredient in Traumalix DOLO gel 5% (D2++, D4+++) (Figure 1E). The individual ingredients of Bepanthen Sensiderm, kindly provided by the manufacturer in the same concentrations as found in Bepanthen Sensiderm, were subsequently patch-tested. They showed a positive reaction to Symcalmin, 5% solution of HPPBA in a vehicle of (1:1) butylene glycol and pentylene glycol (D2−, D4++) (Figure 1F), along with a negative reaction to both, dexpanthenol and pantolactone as well as to sodium benzoate 5% pet and benzyl alcohol 1% pet. Additional patch tests with butylene glycol (5%, 50aq/50alc) (La Roche Posay, La Roche Posay, France) and pentylene glycol (5%, 50aq/50alc) (La Roche Posay, La Roche Posay, France) both showed negative reaction. HPPBA (Figure 2) could not be patch-tested separately. Six unexposed controls were negative to the Symcalmin preparation. Generalized ACD caused by etofenamate in Traumalix DOLO gel 5%, and in addition due to Symcalmin, most likely to its component HPPBA, in Bepanthen Sensiderm, was thus diagnosed. The recommendation for the patient was to avoid both topical and systemic etofenamate-containing non-steroidal anti-inflammatory drugs (NSAIDs) as well as products containing HPPBA. Etofenamate, used most commonly in a gel formulation, is a frequently used NSAID and may cause both allergic and photo-allergic contact dermatitis.5, 6 In our case, etofenamate was considered to be a relevant contact allergen, along with HPPBA, the latter present in a skin-calming cream also containing dexpanthenol. Dexpanthenol,7 and its impurity pantolactone, are cosmetic allergens, the latter potentially even being the actual sensitizer in panthenol-containing products.8 Initially we had suspected these particular haptens to be at the origin of the reported reaction after application of Bepanthen Sensiderm; however, patch testing with both dexpanthenol and pantolactone remained negative, yet pointed towards a new sensitizing culprit, that is, HPPBA. False negative reactions to butylene glycol or pentylene glycol are not probable as at least patch testing with pentylene glycol resulted in a positive reaction (+++) in another patient patch-tested the same week as our patient (data not shown). Unfortunately, HPPBA, which is increasingly used in a wide range of cosmetic products,9 is currently not commercially available for patch-testing. More cases of ACD from this agent might however be encountered in the near future. Discussed patient gave consent for her photographs and medical information to be published in print and online and with the understanding that this information may be publicly available. Open access funding provided by Universite de Lausanne. Olivier Aerts is investigator, speaker and/or consultant for Leo Pharma and L'Oréal/La Roche Posay.