Relationship between formaldehyde and quaternium‐15 contact allergy. Influence of strength of patch test reactions

Background: In groups of patients with formaldehyde allergy, many have positive patch tests to quaternium‐15. Conversely, of patients allergic to quaternium‐15, over half also react to formaldehyde. Objectives: To test our hypothesis that patients with stronger patch test reactions to formaldehyde are more likely to react to quaternium‐15, attesting to the aetiological role for formaldehyde in such co‐reactivity. Methods: Retrospective analysis of all patients patch tested with formaldehyde and quaternium‐15 in the European baseline series between 1994 and 2009 (TRUE test^®). Results: In a group of 86 patients allergic to formaldehyde, 73% co‐reacted to quaternium‐15; in the subgroup of 70 women, the percentage was 83. In both groups, more reactions were observed to quaternium‐15 in the patients with a ++ reaction compared to the patients with a + reaction to formaldehyde. Conversely, stronger reactions to quaternium‐15 were significantly more often associated with formaldehyde sensitivity in a group of 107 patients reacting to quaternium‐15 and a subgroup of 88 women. In men, such effects were not observed and only 5 of 16 (31%) men allergic to formaldehyde also reacted to quaternium‐15. Conclusions: In women, but not in men, stronger reactions to formaldehyde lead to more positive quaternium‐15 patch tests.     

“Slime” contact dermatitis: Case report and review of relevant allergens

Homemade “slime” is currently a popular childhood hobby that can cause allergic and irritant contact dermatitis. We describe a case of hand dermatitis due to homemade “slime” with a positive patch test to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) and MI. The most common potential allergens in “slime” collected from a review of “slime” recipes found on the Internet are reviewed.     

Another look at seasonal variation in patch test results. A multifactorial analysis of surveillance data of the IVDK. Information Network of Departments of Dermatology

There is conflicting evidence concerning seasonal variability of patch test results and no evidence concerning the influence of season on weak-positive, possibly false-positive, irritant reactions, which was analysed in the present study. Data collected in the German Information Network of Departments of Dermatology (IVDK) 1992 to 1997 were combined with external environmental data on temperature and absolute humidity in Germany, and bivariate as well as logistic regression analyses performed concerning the association between reactivity to selected allergens and air temperature and absolute humidity on the respective days of patch testing. Between 39,239 and 41,629 patients had been tested with the 4 allergens considered here. Only formaldehyde exhibited a distinct increase in questionable or irritant as well as weak-positive reactions associated with dry, cold weather. Methylchloroisothiazolinone/methylisothiazolinone and lanolin alcohol showed only a weak, and epoxy resin no, association with climatic conditions. The results indicate that weak-positive reactions, at least to formaldehyde as a prototype of an allergen which is at the same time a marginal irritant, may sometimes be irritant rather than allergic. Patients showing these should be re-tested to improve the poor reproducibilty observed with this allergen.     

Diazolidinyl urea: incidence of sensitivity, patterns of cross-reactivity and clinical relevance

Diazolidinyl urea (DIAZ) is a formaldehyde-releasing preservative used in cosmetics and personal-care products, which has been identified as a sensitizing agent in contact dermatitis. To determine whether DIAZ sensitization is secondary to formaldehyde release or due to its own allergenic properties, we reviewed 708 consecutive patch tests of patients with various dermatologic complaints. Profiles of the 58 individuals (8%) with DIAZ sensitivity were analyzed with respect to sex, age, exposures, and chronicity of dermatitis. Significant coexistent biocide reactivity was demonstrated for DIAZ and formaldehyde (81%); 12% reacted to DIAZ alone. We conclude that the primary mode of sensitization of DIAZ is via formaldehyde release and that independent contact allergy is less frequent.     

Patch testing with formaldehyde and formaldehyde‐releasers: multicentre study in Spain (2005–2009)

Background. Formaldehyde and formaldehyde‐releasers are common causes of allergic contact dermatitis. Objectives. To determine the frequency of sensitization to formaldehyde and seven formaldehyde‐releasers. To establish and characterize groups of patients according to the results of patch testing. Materials and methods. We performed a 5‐year retrospective study, in six Spanish hospitals, of patients with positive patch test reactions to formaldehyde or any of seven formaldehyde‐releasers. Results. The most frequent allergens were formaldehyde (1.72%), imidazolidinyl urea (1.05%), quaternium‐15 (0.88%), and diazolidinyl urea (0.79%). Patients with sensitization to only formaldehyde had a higher frequency of occupational dermatitis (25%) than patients with sensitization to only formaldehyde‐releasers (9.5%). The most common sites of dermatitis were the hands (31.7%) in patients with sensitization to only formaldehyde and the face and legs (31.3% and 24.6%) in patients with sensitization to only formaldehyde‐releasers. We found a subgroup of 25 patients who were sensitized to both imidazolidinyl urea and diazolidinyl urea, and only 6 of these (24%) were also sensitized to formaldehyde. Conclusions. The inclusion of imidazolidinyl urea and diazolidinyl urea in the baseline series of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) should enable better classification of patients allergic to formaldehyde, and could aid in their management.     

The different decomposition properties of diazolidinyl urea in cosmetics and patch test materials

Background. Diazolidinyl urea is a formaldehyde‐releasing compound that releases formaldehyde through its decomposition. However, there have been few reports about the decomposition properties of diazolidinyl urea in cosmetics and patch test materials. Objectives. The aim of this study was to show how diazolidinyl urea decomposes in cosmetics and patch test vehicles, and to determine which cosmetic compounds should be evaluated in patch test studies of diazolidinyl urea. Method. We fractionated diazolidinyl urea‐dissolving buffers or diazolidinyl urea‐containing cosmetics with high‐performance liquid chromatography–photodiode array detector (HPLC‐PDA), and characterized them in liquid chromatography–mass spectrometry (LC‐MS) and ¹H‐nuclear magnetic resonance studies. Diazolidinyl urea‐containing cosmetics and diazolidinyl urea patch test materials were also analysed with HPLC‐PDA and LC‐MS. Results. Diazolidinyl urea was decomposed to (4‐hydroxymethyl‐2,5‐dioxo‐imidazolidine‐4‐yl)‐urea (HU) and (3,4‐bis‐hydroxymethyl‐2,5‐dioxo‐imidazolidine‐4‐yl)‐urea (3,4‐BHU) in most of the cosmetic samples tested. The peak patterns of the patch test materials analysed with the HPLC‐PDA were different from those of the cosmetic samples. Conclusions. The diazolidinyl urea‐derived decomposition products differed between the cosmetics and patch test preparations. To test the contact sensitivity of the diazolidinyl urea present in cosmetics, patch tests with HU and 3,4‐BHU in petrolatum should be performed.     

Frequency of sensitization to 13 common preservatives in Switzerland *

From February 1989 to January 1990, the Swiss Contact Dermatitis Research Group conducted a 1-year study to examine the frequency of sensitization to a series of 13 common preservatives. A group of 2295 consecutive outpatients with suspected allergic contact dermatitis (age range 7–90 years, with a mean age of 42; 911 males, 1384 females) was tested. The %s of positive reactions to the preservatives studied are as follows, in descending order: formaldehyde 5.7%, benzalkonium chloride 5.5%, Kathon CG 5.5%, thimerosal 4.2%, chlorhexidine digluconate 2.0%, DMDM hydantoin 1.7%. paraben mix 1.7%, chloroacetamide 1.5%, Bronopol 1.2%, imidazolidinyl urea 1.0%, quaternium 15 1.0%, triclosan 0.8%, 2,4-dichlorobenzyl alcohol 0.4%. These relatively high values suggest a heavy exposure of the Swiss population to topical preservatives. Compared to previous studies, the sensitization rate to Kathon CG has stabilized in Switzerland over the last 2 years. Sensitization to formaldehyde portrayed impressive geographical variation, with sensitization rates up to 9% in western and only 3% in eastern Switzerland. The low sensitization rate to parabens argues for their inclusion in a medicament or preservative series, rather than in the standard series.