Biomedical subjects
Publications and source records attributed to C Duguid.
Ethics today must focus on 'end of life' concerns, patient autonomy, resource distribution and problems of communication. With ever increasing technology and expanding costs of health services there must eventually be a process of rationing. There must come a time to refuse 'futile' treatment. Unfortunately the law insists on, and doctors are guilty of providing futile treatment.
Photopatch testing, although widely used in the diagnosis of photosensitivity disorders, is not standardized. We performed this study to determine the threshold ultraviolet light A (UV-A) dose required to elicit photopatch test responses. 4 patients with previously positive tests were reexposed to the offending allergen, using an incremental dosage regime. Isopropyl dibenzoylmethane (Eusolex 8020), mexenone (benzophenone-10) and oxybenzone (benzophenone-3) produced positive responses at 1.0, 1.0 and 0.7 J/cm2, respectively. Responses to phenothiazines were deemed phototoxic. These results demonstrate that high doses of UV-A (e.g., 10-15 J/cm2) are unnecessary, and that 5 J/cm2 should become the current standard.
Explore the source record for details and available documents.