The skin allergenic properties of chemicals may depend on contaminants--evidence from studies on coumarin.

Background/aims: Positive patch tests are considered representative of a contact allergy to the tested chemical. However, contaminants and derivatives rather than the suspected chemical itself could be responsible for the allergic skin reactions. Here, we tested the importance of contaminants in the sensitizing and allergenic properties of coumarin in mice and humans.

Nickel release from stainless steels.

In 1994, a study of nickel release and allergic contact dermatitis from nickel-plated metals and stainless steels was published in this journal. It was shown that low-sulfur stainless steel grades like AISI 304, 316L or 430 (S < or = 0.007%) release less than 0.

Dissociation of allergenic and immunogenic functions in contact sensitivity to para-phenylenediamine.

Contact sensitivity to para-phenylenediamine (PPD) is a frequent delayed-type hypersensitivity resulting in contact dermatitis. The aim of the present study, conducted in 16 patients allergic to PPD (as assessed by a positive patch test), was to get better insight into the mechanism of T-cell activation in PPD contact sensitivity. PPD was unable to induce significant proliferation of T cells from a first set of 9 patients.

[Multicenter survey related to the frequency of positive patch tests with mercury and thiomersal].

A multicentric study concerning the frequency of positive allergic patch test reactions to mercury and to thiomersal has been conducted in France and in Belgium among 2,000 adult patients submitted to routine patch testing. 73 (3.6 p.

Contact dermatitis after transcutaneous electric analgesia.

Transcutaneous electric analgesia, based on the gate control theory, is used in stump pain, lumbar pain, traumatic pain following nerve damage and sciatic neuralgia. 3 patients using this method, showed contact dermatitis at the sites of contact of the electrodes. Patch tests were positive with the electrolyte gel, and in 2 cases, with propylene glycol.

[Allergy to preservatives].

This study concerns 465 patients with dermatitis. The clinical history suggested allergy to cosmetics, drugs, industrial products or clothes. These patients were tested with 29 preservatives chosen among the most frequently employed or most sensitising products.

[Allergy to rosin caused by patch tests].

5 commercial patch-test-products were investigated by gas chromatography. Colophony was detected in three of the products, and the allergen was found in the adhesive component.

[Allergologic studies of intolerance to rosin].

Patch-tests made in 13 persons who were allergic to colophony revealed quite different allergologic profiles. Some patients reacted only to abietylic alcohol while others did not react to abietic acid. Methylabietate used as plasticizer in sticking-plasters and especially "hypoallergic" ones, had an allergizing effect in 6 out of 12 cases.

Eau de Javel and prevention of chromate allergy in France.

"Eau de Javel" (liquid bleach) is a common cause of chromate contact allergy. A historical review explains the reasons for the addition of sodium dichromate after the First World War. The chromium content in different brands of eau de Javel has been determined by flameless atomic absorption spectrophotometry.

[Investigation of the allergens of colophony and its derivatives used in the manufacture of sticking-plasters (author's transl)].

Colophony and its derivatives play an important part in intolerances to sticking-plasters. Gas chromatography revealed resinic acids (derivatives) in numerous products of that kind, even in the so-called "hypoallergic" ones. The profiles of the resinic acids contained in some sticking-plasters that are sold in several countries under identic names, are rather different.

Eczemas due to plant allergens in manufactured products.

Intolerance to plant allergens in manufactured products is widespread. Results of epidemiological investigations in STRASBOURG are given. The rate of allergy to sesquiterpenic lactones has fallen since 1974, due to the fact that the use of an ointment containing these lactones has decreased.