[Allergic eczema to wax cloth. Attempts at identification of an allergen].

The coming out of 20 cases of eczema to American cloth, in 1978, motivated a clinical, allergologic and chemical investigation. From a clinical point of view, the lesions were located in areas in contact with American cloth. Cutaneous biopsies, which were carried out in 3 cases, established the allergic eczematous nature of these lesions. Epicutaneous tests were carried out by these patients. With American cloth, results were positive in 20 cases out of 20; six constituents provided by the manufacturer and a standard battery of allergens gave no indication. The chemical analysis of American cloths revealed among others an unknown product which was found in every formulation. This product had a molecular weight of 223; the infra-red spectra and the mass spectra showed a strong analogy with the spectra of alpha-phenyl indole. Tests carried out with alpha-phenyl-indole were positive in 11 cases out of 18; among controls every test was negative.