Contact Photodermatitis Due to Bithionol and Related Compounds

The enigma of chronic photosensitivity

“…Data on the action spectrum for production of erythema on normal appearing skin of patients with PLR have been contradictory. It has generally been accepted that UV-B (290-320 nm) produces an abnormal reaction (Wilkinson, i962ai Jillson & Baughman, 1963;Masuda et al, 1971;Freeman & Knox, 1968Ĉ ripps & Enta, 1971Hjorth & Wilkinson, 1968;Wilkinson, 1962b;Harber, Harris & Baer, 1966;Harber, Targovnik & Baer, 1967), but in one study reactivity to UV-B was normal (O'Quinn, Kennedy & Isbell, 1967). Willis & Kilgman (1968) deliberately photosensitized human subjects to a number of chemicals, and they were unable to detect UV-B sensitivity, but it should be stressed that none of their patients developed the clinical picture of PLR.…”

“…In patients who developed PLR the carrier portion ofthe molecule alone was sufficient to elicit the reaction. Another hypothesis suggested that clones of cells had become persistently photosensitive and that these were responsible in some way for the condition (O'Quinn et al, 1967). Yet another theory was that patients with PLR might not be able to metabolize the haptene (Burry, 1967).…”

SPECTROSCOPIC STUDIES OF CUTANEOUS PHOTOSENSITIZING AGENTS–XII. SPIN TRAPPING STUDY OF THE FREE RADICALS GENERATED DURING THE PHOTOLYSIS OF PHOTO ALLERGENS BITHIONOL and FENTICHLOR

“…Recent reports include amiodarone (Li and Chignell, 1987b), chlorpromazine (Motten et al, 1985) and 2-(4-halophenyl)benzoxazoles (Fery-Forgues and Paillous, 1986). The formation of aryl radicals during the photodehalogenation of polyhalogenated phenols has long been postulated or implicated (Horio, 1984;Johnson, 1984;O'Quinn et al, 1967). Compounds which are structurally related to BT and FT, for example hexachlorophene (Shaffer et al, 1971), TCSA, TBS (Coxon et al, 1965) and Jadit (Jung et al, 1968), all yield dehalogenated products upon UV photolysis.…”