Occupational patch test

The most frequent causes of allergic contact dermatitis in the United States include plants (poison ivy, poison oak, and poison sumac), metallic salts, organic dyes, plastic resins, rubber additives, and germicides.74 The most common skin patch test allergens found to be positive in patients along with potential sources of exposure are shown in Table 32.1.75 In patients with occupational contact dermatitis who were skin patch tested, the common allergens included carba mix, thiuram mix, formaldehyde, epoxy resin, and nickel.76... 

A 58-year-old woman, who had been involved in the manufacturing of glucocorticoid creams and ointments for over 10 years, developed occupational contact sensitization to topical glucocorticoids (472). Patch tests were positive to hydrocortisone, hydrocortisone butyrate, and tixocortol pivalate. Intradermal tests were positive to hydrocortisone succinate, methylpredniso-lone, and prednisolone. An oral challenge with betamethasone 0.75 mg, 2.5 mg, and 8 mg on three consecutive days resulted in no adverse reactions. 

In a study of 1,752 patients considered to have occupational dermatoses, contact dermatitis was the main diagnosis in 1,496 patients (92% women, 83% men). The allergic type, as opposed to the irritant type, was more prevalent in men (73%) than in women (51%). Positive patch tests to chromium (not otherwise specified) occurred in 8% of the women and 29% of the men. Among 280 chromium-sensitized men, 50% were employed in building and concrete work, 17% in metal work, and 12% in tanneries. In the 42 chromium-sensitized women, 20% were in cement work, 19% in metal work, 28% in cleaning, and 15% in laboratory work (Fregert 1975). 

Of about 1000 patients with occupational skin diseases, five had occupational allergic contact dermatitis from spices (11). They were chefs or workers in kitchens, coffee rooms, and restaurants. In all cases the dermatitis affected the hands. The causative spices were garlic, cinnamon, ginger, allspice, and clove. The same patients had positive patch-test reactions to carrot, lettuce, and tomato. 

This case highlights the importance of patch testing with individual components of a suspected product in occupational dermatitis. This reduces the chance of false positive reactions and of missing a relevant allergen. 

A group of 50 catering workers with eczema or dermatitis of the hand or arm were studied for suspected occupational dermatitis. All workers were prick tested with foods that commonly irritated their hands at work, as well as patch tested with garlic 50% in arachis oil, onion 50% in arachis oil, and pieces of the same prick test foods. Seven workers reacted to 50% garlic in oil and one reacted to whole garlic (92). 

DNP in a contact skin test (Beinhauer 1934). Patch tests, scratch tests, intradermal tests, and passive transfer tests with 2,4-DNP performed on 158 people, 117 of whom had hay fever, asthma or urticaria, were all negative (Matzger 1934). Such reactions were not reported in the occupational exposure studies, which involved inhalation and dermal exposure (Gisclard and Woodward 1946 Perkins 1919). 

Rudzki E, Rebandel P, Grzywa Z. 1989. Patch tests with occupational contactants in nurses, doctors and dentists. Contact Dermatitis 20 247-259. 

Allergic contact dermatitis can develop in the working environment. As a prerequisite for allergen avoidance at the workplace, the exact allergen must be identified by patch testing, but in many cases return to the workplace may be impossible. Examples of occupational contact allergens are nickel salts, potassium dichromate or paraphenylene diamine. 

The detailed history and examination of the patient s skin is necessary for the diagnosis of occupational skin disease, in most cases followed by patch testing. Further investigations and visits to the workplace may be necessary. Observation of symptoms after returning the patient to the same workplace is important. Evaluation has the following objectives ... 

FisherAA. 1983. Occupational dermatitis from pesticides Patch testing procedures. Current Contact News 31 483-508. 

Allergic reactions to ylang ylang essential oil, including occupational contact dermatitis, have been reported and confirmed by patch testing (Burdock and Carabin 2008). 

Occupational allergy to cassia and cassia essential oil has been reported and confirmed by patch testing (De Benito and Alzaga 1999 Steger et al. 2000). 

Occupational allergic asthma and rhinitis to passionflower, confirmed by patch testing, were reported in a pharmacy worker who prepared herbal products (Giavina-Bianchi et al. 1997). 

Occupational allergic contact dermatitis from allspice, confirmed by patch testing, was reported in a food service worker (Kanerva et al. 1996). 

Benzoyl peroxide is used mainly in acne treatment and is an irritant. Allergic contact dermatitis to this compound is not infrequent. Eaglstiein (1968) reported two cases. The sensitization rate has been estimated to be 1 %-2.5%. In a human maximization test, 76% became sensitized (Leyden and Kligman 1977). Crossreactions to benzoic acid and related compounds were not found. The drug has been advocated for treatment of chronic leg ulcers. Eight of 16 patients showed positive patch tests to 2% benzoyl peroxide after 6 weeks of leg ulcer treatment with 10% benzoyl peroxide (Jensen et al. 1980). Patients sensitized to benzoyl peroxide may be at risk in certain occupations (e.g., baking and the plastics industry). 

Occupational quinidine contact dermatitis has also been reported (Fernstrom 1965). The patient was an employee of a pharmaceutical company and was required to grind drugs into a powder. A positive patch test to crystals of quinidine sulphate confirmed the already strong clinical evidence. 

In another study by Mancuso et al. it was shown that the occupational contact dermatitis of workers in shoe factories was probably a result of solvents in varnishes and adhesives. This study was based on interviews, medical examinations and patch test series. 

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