Methods of using phenylethenyl compounds having retinoid-like activity

A method for treating dermatoses including psoriasis, in a mammal which method comprises administering a therapeutically effective amount of a compound of the formula ##STR6## in which:

• R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are hydrogen, lower alkyl, halogen or lower alkoxy;
• R.sub.5 is hydrogen or lower alkyl;
• Y is oxygen or sulfur;
• Z is 1-10 carbon straight or branched alkyl, or 2-10 carbon straight or branched chain alkenyl or alkynyl;
• n is 0-5;
• and
• A is COOH, COOR.sub.7, CONHR.sub.7, CON(R.sub.7).sub.2, --CH.sub.2 OH, --CH.sub.2 OR.sub.7, CH.sub.2 OCOR.sub.7, --CHO, CH(OR.sub.8).sub.2, CHOR.sub.9 O, --COR.sub.6, CR.sub.6 (OR.sub.8).sub.2, or CR.sub.6 OR.sub.9 O where R.sub.6 is --(CH.sub.2).sub.m CH.sub.3 where m is 0-4, R.sub.7 is alkyl of 1 to 10 carbons or aryl or alkyl-aryl group, R.sub.8 is lower alkyl, and R.sub.9 is divalent alkyl radical of 2 to 5 carbons, or administering a pharmaceutically acceptable salt of said compound.