Contact allergy investigations in healthcare workers with face mask-related skin disease.

BACKGROUND: During the COVID-19 pandemic, the use of face masks has increased among healthcare workers (HCWs). Questionnaire studies have shown a high frequency of self-reported facial adverse skin reactions. Case reports have been published on face mask-induced allergic contact dermatitis and urticaria. OBJECTIVES: To describe the results of the contact allergy investigations in consecutive HCWs investigated for skin reactions to face masks during the COVID-19 pandemic and the results of the chemical investigations of face masks supplied by the hospital. METHODS: Participants were patch tested with baseline series and chemicals previously reported in face masks not included in the baseline series. Face mask(s) brought by the HCW were tested as is and/or in acetone extract. Chemical analyses were performed on nine different face masks for potential allergens. RESULTS: Fifty-eight HCWs were investigated. No contact allergies were found to the face mask(s) tested. Eczema was the most common type of skin reaction, followed by an acneiform reaction. Colophonium-related substances were found in one respirator and 2,6-di-t-butyl-4-methylphenol (BHT) were found in two respirators. CONCLUSION: Based on this report, contact allergies to face masks is uncommon. Patch test with colophonium-related substances and BHT should be considered when investigating adverse skin reactions to face masks.

Active sensitization to dimethylthiocarbamylbenzothiazol sulphide: An unexpectedly strong rubber contact allergen.

BACKGROUND: The two dialkylthiocarbamyl benzothiazole sulphides, dimethyl-thiocarbamylbenzothiazole sulphide (DMTBS) and diethylthio-carbamylbenzothiazole sulphide (DETBS) were shown to be good markers of both thiuram and mercaptobenzothiazole sensitivity. OBJECTIVES: To investigate if DMTBS and/or DETBS could be better markers of contact allergy to common rubber additives than the ones currently used. METHODS: Sixty-eight dermatitis patients were patch tested with DMTBS and DETBS, both at 1% in petrolatum (pet). Because of late reactions in 10 patients, these were retested to DMTBS and DETBS in serial dilutions. Tetramethylthiuram monosulphide (TMTM) 1.0% pet was also tested. RESULTS: At the initial reading Days 3 and 7, no reactions were noted to DMTBS or DETBS. At retesting, 10 of the 68 (15%) patients reacted positively to lower concentrations of DMTBS than the initial test concentration. Seven of 8 also reacted to TMTM. Three of them had positive reactions to DEBTS. All 10 patients had reactions to more diluted solutions to DMBTS than to DEBTS (p = 0.0077; Mc-Nemar test, two-sided). CONCLUSIONS: Results speak for patch test sensitization to DMTBS with cross-reactivity to TMTM and also DEBTS. DMTBS and DEBTS could be new markers of rubber allergy but a safe test concentration must be found.

Simultaneous patch testing with fragrance markers in the baseline series and the ingredients of fragrance mixes: An update from southern Sweden.

BACKGROUND: Regularly updating the prevalence of fragrance contact allergy (CA) is important. Patch testing with fragrance markers in the baseline series and the ingredients of fragrance mixes (FMs) is still debated. OBJECTIVES: To update the prevalence and clinical characteristics of patients with fragrance CA. To establish the results of patch testing with individual allergens of FMs. METHODS: A retrospective analysis of 3539 patients with dermatitis who were patch tested with the baseline series and FMs ingredients during 2016 to 2020 was performed. RESULTS: The prevalence of fragrance CA was 13%. About 10% of these patients with fragrance CA would be missed if the individual ingredients were not tested. Unlike hydroxyisohexyl 3-cyclohexene carboxaldehyde, there was no decreasing trend of CA to Evernia prunastri (oakmoss) extract after the EU regulation came into force. Patients with CA from only one ingredient of the mixes or having a weak positive reaction to the ingredients were significantly missed when tested with only the fragrance markers in the baseline series. CONCLUSIONS: Patch testing with individual fragrance allergens is crucial for experts to expand knowledge in the fragrance CA field. The concentrations of the allergens in FMs may need to be adjusted to detect patients with fragrance CA, since some were significantly overlooked.

Contact Allergy to Two Aluminum Salts in Consecutively Patch-Tested Dermatitis Patients.

BACKGROUND: Recently, aluminum chloride hexahydrate (ACH) 10.0% petrolatum (pet) was recommended for patch testing to detect aluminum contact allergy. Aluminum lactate (AL) may be as reliable a test substance as ACH. OBJECTIVE: We aimed to investigate the frequencies of aluminum allergy when ACH and AL were used in patch testing consecutive patients. METHODS: Petrolatum preparations of ACH 10.0% and AL 12.0% were added to the baseline series in 2010-2017. Aluminum chloride hexahydrate 10.0% pet was added to the children baseline series from July 1, 2012, to December 31, 2017. RESULTS: A total of 5448 patients were patch tested with the extended baseline series and 196 children with the extended children baseline series. Forty-eight of the 5448 adults (0.9%) and 10 of the 196 children (5.1%) were diagnosed with aluminum contact allergy. A significant difference was found between the aluminum allergy frequencies in children and adults patch tested with ACH in 2013-2017 (P < 0.001). The difference between the frequencies of contact allergies for the 2 aluminum salts is not statistically significant. CONCLUSIONS: Patch testing with ACH and AL demonstrated similar contact allergy frequencies. To detect aluminum allergy, patch testing with ACH 10.0% pet is recommended. Aluminum chloride hexahydrate 10.0% pet should be considered for inclusion in baseline series for patch testing adults and children.

Contact allergy to oxidized linalool and oxidized limonene: Patch testing in consecutive patients with dermatitis.

BACKGROUND: Contact allergy to oxidized (ox.) linalool and ox. limonene has been reported to have a high prevalence, raising the question of inclusion into the baseline series. However, several important issues should be clarified and further investigated before inclusion can be warranted. OBJECTIVES: To report the trends of ox. terpenes allergy in patients with dermatitis, features of the patch test reactions, and clinical characteristics of the patients. METHODS: A retrospective analysis of 5773 patients was performed. All patients were patch tested with baseline series, individual ingredients of fragrance mix I and II, ox. linalool, and ox. limonene from 2013 to 2020. RESULTS: The prevalence rates of contact allergy to ox. linalool and ox. limonene were 7.0% and 5.1%, respectively. Significantly increasing trends of contact allergy were observed. More than 95% of contact allergy cases were identified on Day 3/4. Patients with contact allergy to ox. linalool and ox. limonene were significantly younger than those with contact allergy to other fragrances and were predominantly female. Strong reactions were associated with older age and multiple fragrance allergies. CONCLUSIONS: Contact allergy to ox. linalool and ox. limonene is becoming increasingly important, and findings show intriguing features. More studies concerning the clinical relevance before recommending these substances for screening are required.

Contact allergy to polyhexamethylene biguanide (polyaminopropyl biguanide).

BACKGROUND: Polyaminopropyl biguanide (INCI name) and polyhexamethylene biguanide (PHMB) are polymeric biguanides. PHMB is a broad-spectrum antimicrobial substance used as a preservative in many products. Due to our limited knowledge on PHMB contact allergy frequency and the fact that cases of allergic contact dermatitis to PHMB might be missed, we have included PHMB as a screening allergen since 2016. OBJECTIVE: To report the prevalence of positive patch test reactions to PHMB as a screening allergen in patients with suspected allergic contact dermatitis. METHODS: A retrospective analysis of 1760 patch tested patients from July 2016 to December 2018 was performed. Polyaminopropyl biguanide 2.0% aqua was included in the extended Malmö baseline series during the study period. RESULTS: Of all patients, 1204 (68.4%) were female. Positive patch test reactions were reported in 19 patients (1.1%). The most common sites of lesions were face, head, and neck (52.6%). There was a significant correlation between concomitant reactions to PHMB and other cosmetic-related allergens. CONCLUSION: The prevalence of positive reactions to PHMB was higher than that previously reported. Patch testing with PHMB should be performed in patients with dermatitis who have lesions on the face, head, and neck.

Subjective and Objective Characteristics of Patients Seen at a Psychodermatology Unit: One-year Experience in Malmö, Sweden.

Clinical epidemiological knowledge concerning psychodermatology patients is scarce. The objective of this study was to assess morbidity in a new psychodermatology service. Information was gathered from patient records at the psychodermatology unit in Skåne University Hospital, Malmö, Sweden, from 1 February 2017 to 31 January 2018. All patients were screened with the Hospital Anxiety and Depression Scale (HADS) and the Dermatology Life Quality Index (DLQI) at baseline and after 12 months. Additional information was collated from the patient records. A total of 50 patients were treated during the 12 months, 86% were women, mean age 44 years (standard deviation (SD) 16 years). Itch was present in 72% of patients. Forty-two percent of patients were diagnosed with mood disorders, 30% with personality disorders, and 16% with delusional disorders. At baseline 40% of patients had a DLQI score >11, clinical depression was present in 14%, and clinical anxiety in 28%. These data emphasize the need for access to a multidisciplinary unit for dermatology patients.

Solvent Orange 60 is a potent contact sensitizer in occupational and everyday life.

BACKGROUND: Solvent Orange (SO) 60 is a perinone-type dye that is often used in plastic materials such as spectacle frames and has been shown to cause contact allergy. The first case of SO 60 allergic contact dermatitis caused by spectacle frames was reported in 1999, and the second in 2011. We have recently seen 10 patients, of whom 6 developed dermatitis in the retroauricular/temporal area after wearing plastic spectacles. OBJECTIVES: To report the cause of the dermatitis in the 10 patients and to describe our first case with occupational SO 60 contact allergy. METHODS: In this retrospective study, patch test results of 10 patients, tested with the Swedish baseline series and our specific spectacle and/or plastic series, including SO 60 1.0% pet., in 2011-2017 were analysed. RESULTS: Ten patients, 2 males and 8 females, aged 43 to 71 years, reacted positively to SO 60 1.0% pet., namely, 4 pensioners, 2 nurses, 1 office worker, 1 teacher, 1 shop assistant, and 1 unemployed person. Four of the patients had an atopic history. Patch test reactions varied from + to +++; some had spread >20 cm outside the test area in terms of erythematous, infiltrated skin with papules. Retesting of patient no. 1 with serial dilutions of SO 60 in acetone showed positive reactions down to 1 ppm. Three patients reacted to the extracts of their earpieces. Gas chromatography-mass spectrometry was used to confirm the presence of SO 60 in 2 earpieces. CONCLUSIONS: SO 60 should be included in any spectacle patch test series that may be used. If there is a strong suspicion of contact allergy to SO 60 before patch testing, lowering the test concentration from 1.0% to 0.01% should be considered.

Chromate and amine contact allergies in workers manufacturing precast concrete elements.

BACKGROUND: Five workers from a plant manufacturing concrete wall panels and beams were referred to our department because of suspected occupational dermatitis. When patch tested, 3 workers reacted to potassium dichromate. Four workers reacted to ethylenediamine dihydrochloride, without any obvious exposure. Owing to the high proportion of workers with recent-onset skin disease, an investigation of all workers at the plant was initiated. OBJECTIVES: To investigate the prevalence of occupational dermatitis and contact allergy in the workers at the plant. METHODS: All 24 workers at the plant underwent a clinical investigation and were patch tested. RESULTS: Four cases of allergic occupational contact dermatitis and 3 cases of irritant occupational contact dermatitis were diagnosed. Contact allergy to potassium dichromate was found in 4 workers. All 4 also reacted to ethylenediamine dihydrochloride and/or amines that were present as additives in the cement. CONCLUSIONS: Chromate contact allergy can still be found in concrete workers, despite the legislation regulating the amount of hexavalent chromium (chromate) in cement. Occupational contact allergy to amines can be found in workers exposed to cement and concrete, so amines should be tested in these workers.

Concomitant contact allergies to formaldehyde, methylchloroisothiazolinone/methylisothiazolinone, methylisothiazolinone, and fragrance mixes I and II.

BACKGROUND: Contact allergies to the preservatives formaldehyde and methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) have been reported to appear together at a statistically significant level. Recently, revisions concerning the patch test preparations of MCI/MI, MI and formaldehyde have been recommended for the European baseline series. AIM: To investigate (i) the number of concomitant contact allergies to the preservatives, (ii) the number of concomitant contact allergies to the preservatives and the fragrance mixes (FM I and FM II) and (iii) gender differences. METHODS: Patients tested with the Swedish baseline series during the period 2012-2014 at the Department of Occupational and Environmental Dermatology in Malmö, Sweden were investigated. RESULTS: 2165 patients were patch tested with the baseline series (34% males and 66% females). Contact allergies to formaldehyde and MCI/MI and/or MI were significantly associated (p < 0.001). The associations between contact allergy to MCI/MI and/or MI and FM I and/or FM II, and between formaldehyde and FM I and/or FM II as well as, were statistically significant (p < 0.001). CONCLUSION: Contact allergies to formaldehyde and MCI/MI and/or MI are significantly associated, as well as contact allergies to these preservatives and fragrance allergy. Males and females do not differ significantly concerning contact allergy to fragrances.

Formaldehyde in cosmetics in patch tested dermatitis patients with and without contact allergy to formaldehyde.

BACKGROUND: Formaldehyde is a well-known contact sensitizer. Formaldehyde releasers are widely used preservatives in cosmetics. OBJECTIVES: To survey the release of formaldehyde in cosmetics brought by patients investigated because of suspected allergic contact dermatitis, to compare it with information given by the manufacturers on the packages, and to investigate whether formaldehyde-allergic patients are potentially exposed to more cosmetics releasing formaldehyde than dermatitis patients without contact allergy to formaldehyde. PATIENTS/METHODS: Cosmetics from 10 formaldehyde-allergic and 30 non-allergic patients (controls) matched for age and sex were investigated with the chromotropic acid spot test, which is a semiquantitative method measuring the release of formaldehyde. RESULTS: Formaldehyde was found in 58 of 245 (23.7%) products. Twenty-six of 126 (20.6%) leave-on products released formaldehyde, and 17 of 26 (65.4%) of these were not declared to contain formaldehyde or formaldehyde releasers. Among the rinse-off products, there were 32 of 119 (26.8%) formaldehyde-releasing products, and nine of 32 (28.0%) of these were not labelled as containing formaldehyde or formaldehyde releasers. Five of 10 formaldehyde-allergic patients brought leave-on products with ≥ 40 ppm formaldehyde, as compared with 4 of 30 in the control group (p = 0.029). CONCLUSIONS: Cosmetic products used by formaldehyde-allergic patients that are not declared to contain formaldehyde or formaldehyde-releasing preservatives should be analysed.

Methylisothiazolinone contact allergy is rising to alarming heights also in southern Sweden.

The preservative methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) is a well-known sensitiser and present in most baseline series since at least 20 years. The proportions of MCI/MI are 3:1. MI alone has been used as a preservative in occupational and household products, and cosmetics since less than 10 years. MCI/MI tested at 100 ppm fails to detect a significant percentage of contact-allergic reactions to MI. Our aim was to investigate whether a separate test preparation with MI picks up additional cases of contact allergy to MI not detected with MCI/MI 200 ppm. MI was inserted into the baseline series of the Malmö clinic in 2003 starting at 475 ppm, then 900 ppm, then 1,000 ppm, 1,500 ppm and finally 2,000 ppm. In 5,881 consecutively tested dermatitis patients the contact allergy rate for MI varied between 0.5 and 6.5%, with a marked increase in recent years. The contact allergy rate to MI 2,000 ppm alone, not traced by MCI/MI 200 ppm, varied between 0 and 1.9 %. In conclusion, due to the increase of contact allergy to MI not traced by MCI/MI 200 ppm, MI in water at 2,000 ppm should be tested in a baseline series. Independent of patch test technique a dose of 60 µg/cm should not be exceeded to avoid adverse reactions and particularly patch test sensitisation.

Comparison of three different techniques for application of water solutions to Finn Chambers®.

BACKGROUND: With regard to contact allergy, the dose of a sensitizer per unit skin area is an important factor for both sensitization and elicitation, and therefore a known amount/volume of test preparation should be applied at patch testing. OBJECTIVES: To compare three different techniques for the application of aqueous solutions to Finn Chambers, in order to determine the precision and accuracy of each technique when the recommended 15 µl volume is applied. METHODS: Four technicians applied formaldehyde 1.0% aq. (wt/vol) and methylchloroisothiazolinone/methylisothiazolinone 200 ppm (wt/vol) in sets of 10 onto Finn Chambers, with three different techniques: (i) micro-pipetting; (ii) dripping the solutions; and (iii) dripping the solutions followed by removal of excess solution with a soft tissue. Assessment of the variations was performed with the use of descriptive data. The ability to apply the exact amount was assessed by Fisher's exact test by categorizing each application as in or out of the range 12-18 µl. RESULTS/CONCLUSIONS: The micro-pipette technique had the best accuracy and precision, as well as the lowest inter-individual variation. The technique in which excess solution was removed had good precision, but failed in the application of the defined amount, i.e. 15 µl.

Routine diagnostic patch-testing with formaldehyde 2.0% (0.6 mg/cm2) may be an advantage compared to 1.0%.

Our clinical experience has suggested that the presently recommended patch-test concentration (1.0%) for formaldehyde in the baseline series might be too low. Therefore, consecutively patch-tested dermatitis patients were tested simultaneously with formaldehyde 1.0% and 2.0% (w/v) in aqua. Formaldehyde 1.0% and 2.0% were applied with a micro-pipette (15 microl) to filter paper discs in Finn Chambers (0.30 mg/cm(2) and 0.60 mg/cm(2), respectively). A total of 1397 patients with dermatitis were patch-tested. In all, 68 (4.9%) patients reacted positively to formaldehyde; 37 reacted only to 2.0%, 29 reacted to both concentrations, and 2 reacted only to 1.0%. Significantly more patients were thus diagnosed with contact allergy to formaldehyde 2.0% compared with 1.0% (p < 0.001). We detected 0.1%, 0.4%, and 29.6% irritant reactions to 1.0%, 2.0%, and 3.0% formaldehyde, respectively. We conclude that, with an optimized patch-test technique, doubling the dose per area detects significantly more contact allergies to formaldehyde, but an even higher test concentration causes too many irritant reactions to be usable.