Anthralin

Much like coal tar, anthralin (also called dithranol) is a topical prescription medication that has been used to treat psoriasis for decades. Though anthralin’s action on skin is not clear, it appears to inhibit cell proliferation. It has few serious side effects but can irritate or burn the normal-appearing skin surrounding psoriatic lesions. Anthralin also stains anything it comes into contact with. It is prescribed in a range of concentrations, but the most ef­fective form is a hard paste that is very difficult to apply, requiring a great deal of patience; also, it can’t be used over inflamed lesions, and must not get on the face. There are a variety of regimens for its use, but the negative side effects and cumbersome and time-consuming application process often make it a less-than-desirable option.