TY  - JOUR
T1  - TAr phototoxicity and phototherapy for psoriasis
AU  - Tanenbaum L, Parrish JA, Pathak MA, Anderson R, Fitzpatrick TB
Y1  - 1975/04/01
N1  - 10.1001/archderm.1975.01630160057004
JO  - Archives of Dermatology
SP  - 467
EP  - 470
VL  - 111
IS  - 4
N2  - The phototoxicity of coal tars was determined by comparing the ultraviolet light (UVL) energy required to produce erythema at tar treated sites (minimal phototoxic dose [MPD]) with the energy required to produce the same degree of erythema at untreated control sites (minimal erythema dose [MED]). The ratio of MED/MPD is the phototoxic index (PI). Tars that were phototoxic had a PI of > 1. Using a UVA (320 to 400 nm) and a UVB (290 to 320 nm) light source, 15 subjects and six tars were tested. All tars were phototoxic to UVA but not to UVB (P < 0.0001).Although tar and UVL is a widely accepted treatment for psoriasis (Goeckerman therapy), the light sources employed at normal exposure times provide insufficient UVA energy to produce a phototoxic reaction to the tars that are used. The therapeutic response seen in psoriatic patients treated with tar and UVL should therefore not be attributed to tar phototoxicity.
SN  - 0003-987X
M3  - doi: 10.1001/archderm.1975.01630160057004
UR  - http://dx.doi.org/10.1001/archderm.1975.01630160057004
ER  -