LONGITUDINAL-STUDY OF 1-HYDROXYPYRENE EXC RETION IN URINE AFTER TOPICAL TREATMENT WITH COAL-TAR

In order to study the dermal uptake, time course, and urinary excretio n of polycyclic aromatic hydrocarbons, the concentration of l-hydroxyp yrene in urine was determined by means of high performance liquid chro matography with fluorescence detection before, during, and after the t opical treatment with coal tar in 19 patients suffering from prurigo s implex subacuta, microbial eczema, atopic dermatitis, eczematization a fter scabies, exanthematous lichen ruber, pityriasis lichenoides and c utaneous sarcoidosis. Beginning with a value of 6.04 +/- 2.06 mu g 1-h ydroxypyrene/g creatinine before treatment,the urinary excretion signi ficantly increased during the therapy with coal tar (p < 0.0001 at 3rd , 5th, and 6th day of therapy). A maximum was reached at day 8 of topi cal treatment with a value of 584.35 +/- 191.96 mu g 1-hydroxypyrene/g creatinine (p < 0.002). Already during treatment at day 10 there was a beginning decrease of l-hydroxypyrene to 361.63 +/- 170.13 mu g/g cr eatinine. After the end of treatment, the excretion further decreased reaching a value of 5.31 +/- 2.85 mu g 1-hydroxypyrene/g creatinine at the 10th day after therapy. Skin carcinomas due to therapeutical use of coal tar occur extremely rarely and only after vergoten, non-contro lled use. We suggest that the duration of exposure is the most importa nt factor for the carcinogenic effect of coal tar.