Sensitization to thiourea derivatives among Finnish patients with suspected contact dermatitis

Background: Thiourea derivatives in rubber products may induce contact sensitization and allergic contact dermatitis. Sensitization is most often from neoprene rubber, but the multitude of possible sensitizing products has remained poorly characterized. Objective: The aim of this study was to collect information on the occurrence of thiourea‐related contact allergy and to show novel sources of sensitization. Patients and methods: A mixture of dibutyl‐, diethyl‐, and diphenylthiourea was included in patch test baseline series in five Finnish dermatology clinics during 2002–2007. In addition, an extended series of rubber chemicals was tested in patients with suspected rubber allergy. Sources of sensitization to thioureas were analysed in sensitized patients. Results: Thiourea mix yielded positive patch test reactions in 59 of 15 100 patients (0.39%); 33/59 patients were also tested with individual rubber chemicals. Diethylthiourea was positive in 24/33, diphenylthiourea in 5, and dibutylthiourea in 1 patient. The most common sources of sensitization included various neoprene‐containing orthopaedic braces, sports equipment, and foot wear. Conclusions: The sources of sensitization to thiourea chemicals were detected in most cases. These sources comprise a heterogenous group of products extending from orthopaedic materials to sports equipment.     

Occupational allergic contact dermatitis caused by sterile non‐latex protective gloves: clinical investigation and chemical analyses

Background An increased frequency of occupational contact hand dermatitis among surgical operating theatre personnel has been noticed. Objectives To evaluate patients with occupational contact dermatitis caused by their rubber gloves, and to describe a method for analysing the content of the allergens in the gloves. Materials and methods Patch tests were performed with the baseline series, a rubber chemical series, and the patients' own gloves. A method for analysing 1,3‐diphenylguanidine (DPG) and cetylpyridinium chloride in the gloves was developed. Results Contact allergy to thiuram mix was found in 8 of 16 patients, whereas 12 of 16 patients reacted to DPG. In 7 of 8 patients, contact allergy to cetylpyridinium chloride was found. In the patients' gloves, cetylpyridinium chloride and DPG were detected at higher concentrations on the inside of the gloves than on the outside. Most patients had worked for decades in their present occupations, but their hand dermatitis had only been present for months. Conclusion Contact allergy to DPG in gloves has been disputed, but, in this study, we were able to confirm the presence of DPG and cetylpyridinium chloride in the causative gloves by using a modified method for the analysis. The presence of these chemicals in gloves caused an increase in occupational contact dermatitis in surgical operating theatre personnel.     

Occupational irritant and allergic contact dermatitis among healthcare workers

Contact dermatitis is the most frequent occupational dermatosis and non-specific irritants in addition to specific Type IV sensitization are involved. We reviewed our database for data from 1994 to 1998 and selected 360 consecutive patients working in healthcare environments and experiencing contact dermatitis at their hands, wrists and forearms. We found that allergic contact dermatitis and irritant contact dermatitis were considered to be work-related in 16.5% (72/436) and 44.4% (194/436) of diagnoses, respectively. Occupational irritant contact dermatitis is due to exposure to a wide range of irritants in the workplace, such as soaps, solvents, cleansers and protective gloves, which conspire to remove the surface lipid layer and/or produce cellular damage. In this study the major relevant aetiological agents that induced occupational allergic contact dermatitis were: nickel sulphate (41 patch positivities), components of disinfectants [glutaraldehyde (5) and benzalkonium chloride (7)] and rubber chemicals [thiuram mix (15), carba mix (9) and tetramethylthiuram monosulphide (6)]. The best treatment for allergic contact dermatitis is to avoid those allergens causing the rash. Whenever this is not possible, contact with them needs to be reduced using properly selected protective gloves. Finally, subjects with atopic dermatitis should avoid 'wet work' and contact with irritants, because atopic dermatitis is significantly associated with irritant contact dermatitis.     

Occupational airborne allergic contact dermatitis from azithromycin

The Dutch government has recently taken initiatives to improve the protection of labourers against diseases which are related to their work, and most especially, to reduce the rapidly increasing number of patients who have to definitely stop working and who, eventually, end up being dependent on social welfare. Firstly, a number of new laws have been adopted which define the responsibilities of both the employers and the employees. Secondly the cooperation is stimulated between the Dermatologist and the Occupational Health Physician of the patient. The latter is (according to law) employed by the employer of the patient and regularly visits the place of work. We now had the opportunity to treat and study both the social, medical and occupational aspects of a patient's case simultaneously.
We decided to eliminate the existing hesitation of consulting or referring, as well as the barriers created by matters of procedure, bureaucracy and waiting lists. In our paper we discuss the above‐mentioned laws and regulations, and the way in which cooperation takes place between the doctors. We will present figures showing the effects of this approach on sickleave.     

Occupational allergic contact dermatitis caused by isocyanates

Between 1978 and 2001, 22 patients were diagnosed with occupation-related allergic contact dermatitis from isocyanates and/or polyurethanes in our clinic. 13 had a positive reaction to the isocyanates, of whom 10 also reacted to diaminodiphenylmethane (MDA), which is used in the production or processing of isocyanates and polyurethanes; 9 reacted only to MDA. The object of the present study was to identify the trades and industries responsible for the development of contact allergy to these resins. Such patients must be patch tested with the isocyanates contacted at work, and account must be taken of positive reactions to MDA as a marker for isocyanate sensitivity.     

Occupational allergic contact dermatitis in construction workers

We report the patch test results of 449 con in met ion workers who came as patients to tine Occupational Dermatology Service of the Instituto National de Medicina y Seguridad del Trabajo in Madrid between 1989 and 1993. 90.8%. of them were patch tested, because they had cutaneous lesions or a clinical history suggestive of occupational dermatitis. 65.5% (268) of those patch tested showed one or more reactions connected with their work. Chromate at 411 was the main allergen. followed by cobalt, 20.5% nickel. 10%, and epoxy resin. 7.5%. 25.9% (106) of patients showed sensitization to rubber components, the majority at 20.7%, to thiuram mix, with TETD being the main allergen.     

Occupational allergic contact dermatitis from champignon and Polish mushroom

Capsicum peppers are widespread both in and out the kitchen. "Human hand" is a contact dermatitis resulting from the direct handling of peppers. Capsaicin also is found in topical agents for treatment of postherpetic neuralgia, diabetic neuropathy and arthritis. The oleoresin of capsicum is considered a powerfull irritant capable to induce irritant contact dermatitis and non‐immunological contact urticaria. A 81 year‐old man with a severe itchy macular and papular rash induced by Capsidol® initially located over the shoulder and sudden spread over the thorax is presented. A dense dermal mononuclear cell infiltrate and spongiosis suggested the diagnosis of contact dermatitis. Negative open tests and a positive patch test reaction (++ 96 hours) using the trade cream Capsidol®(capsaicin 5%) led us to contact with the Pharmaceutical Company Viñas. They provided us the components of the cream: capsaicin, isopropyl myristate, estearic acid (DERVACID 3148), propylene glycol, glycerin monomyristate (ESTOL3650GMM), AMPHISOL K, Cetyl alcohol (NACOL 16–85), benzyl alcohol, diazolidinyl urea (GERMALL II), p‐hydroxybenzoate–methylsodium (NIPAGIN M sódic), p‐hydroxybenzoate propyl (NIPASOL M). Capsaicin in benzyl alcohol at 0,075% was open tested with negative results. Only patch test with capsaicin was positive (++) at 48/96 hours and the excipient components at the appropiate concentrations were all negative. Patch test biopsy showed an eczematous pattern. Twenty controls showed negative results. This case is probably an allergic reaction but shows how still remains difficult to distinguish among allergic and irritative cutaneous reactions.