Compositae sensitivity among patients with contact dermatitis: value of compositae oleoresins in a standard test series.

Patch tests with 24 Compositae species were performed on 81 patients suspected of having a plant dermatitis, of whom 16 had positive reactions to various species. When Compositae were included in the standard series, 10 of 488 consecutive patients (2%) were found to be sensitive to one or more species. Most of the positive test reactions were relevant. Fourteen of 16 sensitivities could have been detected by testing with two mixtures of Compositae. Alantolactone could not serve as a screening agent, since four of seven Compositae-sensitive patients had negative reactions to it. Concomitant reactions to balsams were found in four of 10 patients with unexpected sensitivy to Compositae. The clinical pattern of Compositae dermatitis may be that of a lichenified photo dermatitis. These cases are invariably missed, unless patch tests with Compositae are performed. Another group of patients have hadn eczema and also require patch tests with Compositae for etiological diagnosis. Because positive, relevant reactions are common, inclusion of a safe and reliable Compositae screening test in the standard series is urgently required. At the present stage, however, our test materials are sometimes irritant and they have occassionally caused active sensitization.