TARS AND TAR OILS CAN REDUCE THE THICKNESS OF THE EPIDERMIS. THEY ARE ANTIPRURITIC AND MAY BE WEAKLY ANTISEPTIC. THEY ARE USED TOPICALLY IN ECZEMA, PSORIASIS, DANDRUFF, SEBORRHOEIC DERMATITIS, AND OTHER SKIN DISORDERS. COAL TAR PREPARATIONS HAVE LARGELY REPLACED THE USE OF WOOD TARS. ULTRAVIOLET (UVB) LIGHT INCREASES THE EFFICACY OF COAL TAR IN THE TREATMENT OF PSORIASIS.
SOME WOOD TARS, INCLUDING CREOSOTE HAVE BEEN USED IN EXPECTORANT PREPARATIONS. TAR HAS ALSO BEEN USED IN HOMOEOPATHIC MEDICINE.