Isothiazolinones in commercial products at Danish workplaces.

BACKGROUND: In recent years, a steep increase in the frequency of occupational contact allergy to isothiazolinones has been reported from several European countries. OBJECTIVE: To examine the extent and occurrence of isothiazolinones in different types of product at Danish workplaces. METHODS: Seven different isothiazolinones were identified in the Dictionary of Contact Allergens: Chemical Structures, Sources, and References from Kanerva's Occupational Dermatitis. By use of the chemical names and Chemical Abstracts Service numbers for these chemicals, information on products registered in the Danish Product Register Database (PROBAS) was obtained. RESULTS: All seven isothiazolinones were registered in PROBAS. The top three isothiazolinones registered were: benzisothiazolinone (BIT), registered in 985 products, methylisothiazolinone (MI), registered in 884 products, and methylchloroisothiazolinone (MCI)/MI, registered in 611 products. The concentration ranges were 0.01 ppm to 45% for BIT, 0.01 ppm to 10% for MI, and 0.01 ppm to 14.1% for MCI/MI. The most common product type was 'paint and varnish'; five of the seven isothiazolinones were registered in this type of product. CONCLUSION: Isothiazolinones are present in multiple products registered for use at workplaces, and may occur in high concentrations.

Patch testing with methylchloroisothiazolinone/methylisothiazolinone 200 ppm aq. detects significantly more contact allergy than 100 ppm. A multicentre study within the European Environmental and Contact Dermatitis Research Group.

BACKGROUND: Methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are the active ingredients in commonly used preservative systems (e.g. Kathon CG(®)). MCI/MI is present in the European baseline patch test series at 100 ppm aq. Since 1986, 200 ppm (dose 0.006 mg/cm(2)) has been used in Sweden without causing skin irritation. Centres in Spain, the United Kingdom and Ireland have also used 200 ppm in their baseline series. OBJECTIVES: To find the optimal patch test concentration for MCI/MI. MATERIALS AND METHODS: MCI/MI 100 ppm aq. and MCI/MI 200 ppm aq. were simultaneously patch tested in 3300 consecutively tested dermatitis patients at eight European patch test clinics and one US patch test clinic. With the Finn Chambers(®) technique (diameter 8 mm), 15 µl was micropipetted on to the filter paper in the chamber. The corresponding volume for Van der Bend(®) chambers was 20 µl, and that for IQ Chambers(®) was 25 µl. RESULTS: Contact allergy to MCI/MI at 100 and 200 ppm was found in 1.2% and 2.1% of patients, respectively (p < 0.001). CONCLUSIONS: MCI/MI 200 ppm aq. (dose 0.006 mg/cm(2) ) diagnoses significantly more contact allergy than the presently used concentration of 100 ppm (dose 0.003 mg/cm(2)), without resulting in more adverse reactions. MCI/MI at 200 ppm should therefore be considered for inclusion in the European baseline test series.

Contact allergy to common ingredients in hair dyes.

BACKGROUND: p-Phenylenediamine (PPD) is the primary patch test screening agent for hair dye contact allergy, and approximately 100 different hair dye chemicals are allowed. OBJECTIVES: To examine whether PPD is an optimal screening agent for diagnosing hair dye allergy or whether other clinically important sensitizers exist. METHODS: Two thousand nine hundred and thirty-nine consecutive patients in 12 dermatology clinics were patch tested with five hair dyes available from patch test suppliers. Furthermore, 22 frequently used hair dye ingredients not available from patch test suppliers were tested in subgroups of ~500 patients each. RESULTS: A positive reaction to PPD was found in 4.5% of patients, and 2.8% reacted to toluene-2,5-diamine (PTD), 1.8% to p-aminophenol, 1% to m-aminophenol, and 0.1% to resorcinol; all together, 5.3% (n = 156). Dying hair was the most frequently reported cause of the allergy (55.4%); so-called 'temporary henna' tattoos were the cause in 8.5% of the cases. p-Methylaminophenol gave a reaction in 20 patients (2.2%), 3 of them with clinical relevance, and no co-reaction with the above five well-known hair dyes. CONCLUSIONS: Hair dyes are the prime cause of PPD allergy. PPD identifies the majority of positive reactions to PTD, p-aminophenol and m-aminophenol, but not all, which justifies additional testing with hair dye ingredients from the used product.

Patch testing with 2.0% (0.60 mg/cm 2) formaldehyde instead of 1.0% (0.30 mg/cm 2) detects significantly more contact allergy.

BACKGROUND: The currently used patch test concentration for formaldehyde is 1.0% (wt/vol) in water. However, clinical experience and previous studies suggest that 1.0% might be insufficient for detecting an optimized number of clinically relevant cases of contact allergy to formaldehyde. OBJECTIVES: To validate earlier patch test results for comparison of 1% (wt/vol) and 2% (wt/vol) formaldehyde in water, and to investigate co-reactivity with quaternium-15. MATERIALS AND METHODS: In 12 dermatology clinics, 3591 patients were routinely patch tested simultaneously with 2.0% (wt/vol) (0.60 mg/cm(2)) and 1.0% (wt/vol) (0.30 mg/cm(2)) formaldehyde. Micropipettes were used for delivering the exact dosage of the allergen. RESULTS: Significantly more patients reacted to 2.0% formaldehyde than to 1.0% (3.4% versus 1.8%, p < 0.001). Overall, there were no sex differences between those reacting positively to 2.0% and 1.0%. Of 25 quaternium-15-positive patients, 4 (0.1%) reacted positively without reacting to formaldehyde. CONCLUSION: On the basis of the results of this multicentre study, as well as of previous studies, it can be suggested that 2.0% (wt/vol) in water formaldehyde should be used in routine patch testing in the baseline series.

Fragrance allergy: assessing the safety of washed fabrics.

BACKGROUND: Previously, a quantitative risk assessment suggested there was no risk of induction of fragrance allergy from minor residues of fragrance chemicals on washed fabrics. OBJECTIVE: To investigate whether there was any risk of the elicitation of contact allergy from fragrance chemical residues on fabric in individuals who were already sensitized. METHODS: Thirty-six subjects with a positive patch test to isoeugenol (n = 19) or hydroxyisohexyl 3-cyclohexene carboxaldehyde (n = 17) were recruited. Dose-response and fabric patch tests were performed, respectively, with filter paper and a cotton sample loaded with fragrance in ethanol-diethylphthalate (DEP) and applied in a Finn Chamber or a Hill Top Chamber. RESULTS: Only two subjects reacted to an isoeugenol patch test concentration of 0.01% (>20x the estimated likely skin exposure level), none reacted to lower concentrations. Of 36 subjects, 18 reacted to the fabric patch treated with ethanol-DEP vehicle alone and 20 to the fragrance-chemical-treated fabric patch. These were only minor non-specific skin reactions. They were also quite evenly distributed between the two fragrance chemical allergic groups. CONCLUSIONS: On the basis of the examples studied, fragrance chemical residues present on fabric do not appear to present a risk of the elicitation of immediate or delayed allergic skin reactions on individuals already sensitized.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Formaldehyde-releasers in clothes: durable press chemical finishes. Part 1.

This is one of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy and in this paper formaldehyde-releasers used as durable press chemical finishes (DPCF) in textiles are discussed. The literature on allergy to DPCF since 1980 is presented in two parts. Part 1 (this article) presents a short historical overview of the problems with formaldehyde in clothes and discusses the chemistry of durable press chemical finishes, legislation in various countries, and studies on the amount of formaldehyde present in clothes. In addition, the DPCF that have caused contact allergy are presented with CAS, synonyms, molecular formula, chemical structure, applications, and patch test studies. In the forthcoming part 2, the frequency of sensitization to DPCF, occupational contact sensitization, relevance of patch test reactions, and relationship to formaldehyde contact allergy will be reviewed, followed by a discussion of both parts of the article together.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Part 2. Formaldehyde-releasers in clothes: durable press chemical finishes.

This is the second part of a review article on formaldehyde-releasers used as durable press chemical finishes (DPCF) in textiles. The early finishes contained large amounts of free formaldehyde, which led to many cases of allergic contact dermatitis to clothes in the 1950s and 1960s. Currently, most finishes are based on modified dimethylol dihydroxyethyleneurea, which releases less formaldehyde. Nevertheless, recent studies in the United States and Israel have identified patients reacting to DPCF, considered to have allergic contact reactions to clothes, either from formaldehyde released by the DPCF therein or from the DPCF per se (in patients negative to formaldehyde). However, all studies had some weaknesses in design or interpretation and in not a single case has the clinical relevance been proven. The amount of free formaldehyde in most garments will likely be below the threshold for the elicitation of dermatitis for all but the most sensitive patients. The amount of free cyclized urea DPCF in clothes is unlikely to be high enough to cause sensitization. Patch test reactions to formaldehyde-releasing DPCF will in most cases represent a reaction to formaldehyde released from the test material.

Contact sensitisation in hand eczema patients-relation to subdiagnosis, severity and quality of life: a multi-centre study.

BACKGROUND: Contact sensitisation has been identified as a factor associated with poor prognosis for patients with hand eczema. OBJECTIVES: To study implications of contact sensitisation with respect to severity, quality of life (QoL) and subdiagnosis of hand eczema. METHODS: The study was performed as a multi-centre, cross-sectional study from 10 European clinics. All patients were patch tested, and severity of hand eczema assessed by Hand Eczema Severity Index. A multi-variate analysis was performed to explore which factors influenced severity, QoL and sick leave. RESULTS: A total 416 patients were included, and 63% had contact sensitisation to one or more of the tested allergens. More women (66%) than men (51%) were sensitized. No significant association was found between sensitisation to specific allergens, disease severity, QoL or diagnostic subgroups. High age, male sex, atopic eczema and presence of contact sensitisation were independent risk factors for increased severity as measured by Hand Eczema Severity Index. Furthermore, the severity of hand eczema increased by the number of contact sensitisations detected (P = 0.023). High age and personal history of atopic eczema were independent risk factors for low QoL, as measured by Dermatology Life Quality Index, and atopic eczema as well as allergic contact dermatitis as subdiagnosis was associated with increased sick leave. CONCLUSION: Diagnostic subgroups were not found to be related to specific allergens. Contact sensitisation was found to be a risk factor for increased severity of hand eczema, as did high age, male sex and atopic eczema.

Contact allergy in chronic leg ulcers: results of a multicentre study carried out in 423 patients and proposal for an updated series of patch tests.

BACKGROUND: There is a lack of prospective studies investigating contact sensitization in patients with chronic leg ulcers. OBJECTIVES: To determine the frequency of contact sensitization in patients with chronic leg ulcers using a special series of patch tests and to determine whether the number of sensitizations was correlated with the duration of the chronic leg ulcers. PATIENTS/METHODS: Multicentre study carried out in patients with chronic leg ulcers; patch tests with the European baseline series and with an additional 34 individual allergens or mixes and 3 commercial products. RESULTS: Of the 423 patients (301 women, 122 men, mean age 68.5 years) with chronic leg ulcers, 308 (73%) had at least one positive patch test with 3.65 positive patch tests per patient. The main allergens were Myroxylon pereirae (41%), fragrance mix I (26.5%), antiseptics (20%), and corticosteroids (8%). The number of positive tests per patient was not correlated with the cause of ulcer but was increased with the duration of the ulcer with a statistical difference between the group of the <1 year compared with the group >10 years duration. CONCLUSIONS: From this large prospective multicentre study, polysensitization is frequent in patients with chronic leg ulcers, increasing with the duration of the ulcer. We propose avoidance of topical antiseptics and ointments containing perfumes in patients with chronic leg ulcers and an updated patch test series for investigating these patients.

Marking patch tests sites: description of a practical, clean, durable and inexpensive method.

We propose an original method to mark patch test sites. A transparency is applied on the patient's back, surrounding patch tests, immediately after their application. Marks are performed with an erasable pen on test sites and on permanent skin lesions like naevi. For further readings performed after patch test removal, the transparency applied on the patient's back permits the attribution of a positive reaction. This method is clean (without ink marks on skin and without contamination of clothing), more comfortable for the patient (allowing back washing immediately after the 1st reading, never inducing allergy to inks), durable (permitting delayed readings after several days or weeks) and inexpensive (because transparencies can be reused).

Allergic contact dermatitis from shellac in mascara.

We report 6 cases of allergic contact dermatitis of the eyelids due to mascara. Allergy occurred in women aged 17-34 years, between September 1999 and June 2001. The main ingredient responsible for allergy was shellac, which gave positive patch test reactions in 5/5 patients. This resinous substance is mainly used in cosmetics, food and industry. The exact nature of the hapten remains unknown, and its presence and level in shellac can vary with the source and the treatments applied to it. One patient was also sensitized to quaternium-22, a quaternary ammonium compound in the cosmetic. These reports underline the rôle of networks, such as REVIDAL-GERDA, in monitoring the emergence of contact allergens and disseminating such information among the medical community.