[Allergy investigations in eczema]. / Enquête allergologique dans l'eczéma.

Investigation of allergy is of major importance in the diagnosis of eczema. It is mainly based on patient history: personal and familial atopic antecedents, possible contact with allergens at the work-site, in the household or during leisure activities, or in topical medications, cosmetics or clothing. Among complementary examinations, detection of eosinophilia or elevated IgE has no practical application, but sometimes the presence of specific IgE can be useful. In fact, the most important examinations are skin tests, especially patch tests, which are indispensable in contact dermatitis, and in rare cases, patch tests.

[Clinical forms of skin manifestations in allergy to perfume]. / Formes cliniques des manifestations cutanées d'allergie aux parfums.

Perfumes are increasingly used in an ever wider variety of fields, including perfumes proper, cosmetic products, hygienic products, drugs, detergents and other household products, plastics, industrial greases, oils and solvents, foods, etc. Their composition is usually complex; it involves numerous natural and synthetic sweet-smelling constituents, more than 5,000 of which are known (13). Perfumes may produce toxic and, more often, allergic respiratory disorders (asthma), as well as neurological (10) and cutaneous disorders. They are the most common cause of skin allergy to cosmetic products (1, 11) and one of the most important causes of skin allergy to topical drugs or even to syrups which may reactivate contact dermatitis (24). People engaged in the manufacturing of these products may become sensitized to perfumes.

[Allergy to preservatives]. / Allergie aux conservateurs.

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. Seven french clinics of Dermatology were involved in this study during one year. The patients' age varied between 2 years old and 80 years old. Positive reactions were seen mostly with formaldehyde (4.7 p. 100), Bronopol (4.7 p. 100), ammoniated mercury chloride (3.8 p. 100), benzoic acid (2.1 p. 100), sodium benzoate (1.9 p. 100), parabens (1.9 p. 100), dichlorophen (1.7 p. 100), chloracetamid (1.5 p. 100), benzyl benzoate (1.5 p. 100), Germall 115 (1.2 p. 100), butylhydroxyanisol (1 p. 100) and Dowicil (0.8 p. 100). The incidence of sensitivity to formaldehyde, Bronopol, ammoniated mercury chloride is too high; their use should decrease. Patients sensitive to benzoic acid, benzyl benzoate are not rare. Chloracetamid whose frequency of uses seems to be rather low is a very sensitising product. Parabens which are widely used were seldom found positive; nearly all cases are caused by topical medications.

[Contact urticaria in atopic patients. Apropos of 2 cases]. / L'urticaire de contact chez l'atopique. A propos de deux observations.

Contact urticaria appears half an hour after application of allergens on skin area of contact. It is favoured by atopy. Two cases are reported. 16-years-old boy had dermatitis of perioral area, hands and more slightly nape of the neck with urticaria due to local application of potato, carrot and apple. Avoiding those allergens cleared urticaria and dermatitis. 45-years-old woman had face and hands dermatitis associated with contact urticaria to potato and banana on those areas. She had cold urticaria as well. A positive passive transfer (Prausnitz-Küstner) was only seen with potato and banana. It is likely that contact urticaria in the atopics is still under-estimated. Scratching may probably lead to dermatitis. Dermatitis of these two patients could be explained by this way.