Sedation, however, is a side effect of widespread application and irritation has been noted by patients. Tar Preparations Coal tar preparations may have antipruritic and anti-inflammatory effects on the skin. Crude coal tar extracts were used to reduce skin inflammation before the availability of topical corticosteroids. Newer coal tar products have been developed that are more acceptable with respect to odor and staining of clothes than some older products. A moisturizer applied over the tar preparation will decrease the drying effect on the skin.
Some patients prefer a tar compounded in an ointment or cream base.
To increase compliance with use, tar preparations may be recommended at bedtime. The preparation is then removed by washing in the morning, thus eliminating the concern about odor during the day and limiting staining of daytime clothing. Tar preparations should not be used on acutely inflamed skin, since this may result in additional skin irritation. Side effects associated with tars include folliculitis and, occasionally, photosensitivity. Tar shampoos are often beneficial for scalp involvement.