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Determination of threshold UV‐A elicitation dose in photopatch testing
Author(s) -
Duguid C.,
O'Sullivan D.,
Murphy G. M.
Publication year - 1993
Publication title -
contact dermatitis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 96
eISSN - 1600-0536
pISSN - 0105-1873
DOI - 10.1111/j.1600-0536.1993.tb03536.x
Subject(s) - phototoxicity , benzophenone , dermatology , medicine , photosensitivity , ultraviolet a , ultraviolet radiation , chemistry , photochemistry , radiochemistry , biochemistry , physics , quantum mechanics , in vitro
Photopatch testing, although widely used in the diagnosis of photosensitivity disorders, is not Standardized. We performed this study to determine the threshold ultraviolet tight 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 oxybeozone (benzophenone‐3) produced positive responses at 1.0, 1.0 and 0.7 J/cm 2 , respectively. Responses to phenothiazines were deemed phototoxic. These results demonstrate that high doses of UV‐A (e.g., 10–15 J/cm 2 ) are unnecessary, and that 5 J/cm 2 should become the current Standard.