Sensitization and cross-reactivity patterns of contact allergy to diisocyanates and corresponding amines: investigation of diphenylmethane-4,4'-diisocyanate, diphenylmethane-4,4'-diamine, dicyclohexylmethane-4,4'-diisocyanate, and dicylohexylmethane-4,4'-diamine.

BACKGROUND: Isocyanates are used in polyurethane production. Dermal exposure to isocyanates can induce contact allergy. The most common isocyanate is diphenylmethane diisocyanate used for industrial purposes. The isomer diphenylmethane-4,4'-diisocyanate (4,4'-MDI) is used in patch testing. Diphenylmethane-4,4'-diamine (4,4'-MDA) is its corresponding amine. Concurrent reactions to 4,4'-MDI and 4,4'-MDA have been reported, as have concurrent reactions to 4,4'-MDI and dicyclohexylmethane-4,4'-diisocyanate (4,4'-DMDI). OBJECTIVES: To investigate the sensitization capacities and the cross-reactivity of 4,4'-MDI, 4,4'-MDA, 4,4'-DMDI, and dicyclohexylmethane-4,4'-diamine (4,4'-DMDA). METHODS: The guinea-pig maximization test (GPMT) was used. RESULTS: The GPMT showed sensitizing capacities for all investigated substances: 4,4'-MDI, 4,4'-MDA, 4,4'-DMDI, and 4,4'-DMDA (all p < 0.001). 4,4'-MDI-sensitized animals showed cross-reactivity to 4,4'-MDA (p < 0.001) and 4,4'-DMDI (all p < 0.05). 4,4'-MDA-sensitized animals showed cross-reactivity to 4,4'-DMDA (p = 0.008). CONCLUSION: All of the investigated substances were shown to be strong sensitizers. Animals sensitized to 4,4'-MDI showed cross-reactivity to 4,4'-MDA and 4,4'-DMDI, supporting previous findings in the literature. The aromatic amine 4,4'-MDA showed cross-reactivity to the aliphatic amine 4,4'-DMDA.

Contact allergy to epoxy hardeners.

BACKGROUND: Diglycidylether of bisphenol A resin is the most important sensitizer in epoxy systems, but a minority of patients develop concomitant or solitary contact allergy to epoxy hardeners. At the Finnish Institute of Occupational Health, several in-house test substances of epoxy hardeners have been tested in a special epoxy compound patch test series. OBJECTIVES: To analyse the frequency and clinical relevance of allergic reactions to different epoxy hardeners. METHODS: Test files (January 1991 to March 2013) were screened for contact allergy to different epoxy hardeners, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure. RESULTS: The most commonly positive epoxy hardeners were m-xylylenediamine (n = 24), 2,4,6-tris-(dimethylaminomethyl)phenol (tris-DMP; n = 14), isophorone-diamine (n = 12), and diethylenetriamine (n = 9). Trimethylhexamethylenediamine (n = 7), tetraethylenepentamine (n = 4), and triethylenetetramine (n = 2) elicited some reactions, although most patients were found to have no specific exposure. Allergic reactions to hexamethylenetetramine, dimethylaminopropylamine and ethylenediamine dihydrochloride were not related to epoxy products. CONCLUSIONS: Tris-DMP is an important sensitizer in epoxy hardeners, and should be included in the patch test series of epoxy chemicals.

Erythema multiforme after contact dermatitis in response to an epoxy sealant.

A case of erythema multiforme associated with an allergic contact dermatitis in response to an epoxy-based compound is presented. Patch tests revealed a positive reaction to both the epoxy resin and the hardener. Chemicals applied directly to the skin should be considered as a potential cause of erythema multiforme.

Occupational asthma caused by a hardener containing an aliphatic and a cycloaliphatic diamine.

An otherwise healthy 44-yr-old man experienced a serious attack of bronchial obstruction after working with resins and hardeners, releasing fumes of a mixture of an alipathic and a cycloaliphatic diamine hardener. Eight hours after deliberate challenge with the hardener a large increase of airway resistance was found. Seventy-two hours after challenge, eosinophilia in the bronchoalveolar lavage (BAL) fluid together with a decrease of peripheral eosinophils was seen. After cessation of contact with this hardener, no more acute episodes occurred, although maintenance treatment with a topical corticosteroid and a beta 2-agonist remained necessary. A BAL performed 1 yr later showed a normal cell distribution. The results suggest that these aliphatic and cycloaliphatic diamine hardeners may be occupational hazards. Eosinophil inflammation may play a causal role.

[Scleroderma and scleroderma-like diseases caused by environmental pollutants]. / Sklerodermie und Sklerodermie-ähnliche Erkrankungen durch Umweltsubstanzen.

For the stimulation of research on scleroderma and the prophylaxis of occupational scleroderma-like diseases and the prevention of iatrogenic injuries, respect., it is important to know the inducing environmental substances. Plastics (vinyl chloride, epoxy resins), solvents (chlorinated, aromatic and aliphatic hydrocarbons), drugs (bleomycin, pentazocine), cocaine (abuse) and contaminated rapeseed oil are more or less able to induce scleroderma-like diseases. Vinyl chloride disease is the best known among these. The toxic oil syndrome represents the most inglorious example of the recent time. Paraffin and silicon can act as adjuvants and induce a progressive systemic sclerosis. In our studies it could be shown, that silica is able to induce not only a silicosis, but also a true progressive systemic sclerosis after long term exposure. Acknowledgment of such cases as an occupational disease is justified and regulated by law in the German Democratic Republic.

An attempt to improve diagnostics of contact allergy due to epoxy resin systems. First results of the multicentre study EPOX 2002.

Epoxy resin systems (ERSs) are a frequent cause of occupational allergic contact dermatitis. Sensitization occurs not only to the resins, but also to hardeners and reactive diluents. However, only a fraction of the ERS components currently in use are available for patch testing. With the multicentre study EPOX 2002, we attempted to improve diagnostics in this field by patch testing with components currently used in ERSs. During the first study period (October 2002 to July 2003), in addition to commercially available ERS patch test substances, 16 study substances (1 resin, 9 hardeners and 6 reactive diluents) were patch tested in 70 patients with suspected contact allergy due to ERSs and 22 patients with a prior positive patch test reaction to epoxy resin (ER) in the standard series. Most frequently, allergic reactions to ER based on diglycidyl ether of bisphenol A and F were observed (55.2% and 43.7%, respectively). Agreement between positive reactions to both resins, which can be explained by immunological cross-sensitization and/or coexposure, was substantial [Cohen's kappa 0.65 (95% CI: 0.49-0.80)]. Among the reactive diluents, 1,6-hexanediol diglycidyl ether (1,6-HDDGE) and 1,4-butanediol diglycidyl ether (1,4-BDDGE) were the most frequent allergens, with 19.5% and 18.4% positive reactions, respectively. Although agreement between positive reactions to 1,6-HDDGE and 1,4-BDDGE was even better than with the 2 resins, the sample size is considered too small to decide reliably whether 1,6-HDDGE alone could serve as a marker allergen for both. Allergic reactions to p-tert-butylphenyl glycidyl ether and to phenyl glycidyl ether (PGE) occurred in 11.5% of the patients tested, with only moderate agreement. All patients positive to cresyl glycidyl ether (6.8%) also reacted to PGE. Of the hardeners tested, m-xylylene diamine was the most frequent allergen (13.8%), followed by isophorone diamine (5.7%). No reactions were observed to several substances, the test concentration of which may have been too low and will be increased in the future.