Psoriasis is a chronic inflammatory disease of the skin with a likely immunologic basis. Hyperproliferation of epidermal cells leads to thickened, often scaly skin. Lesions usually develop slowly but may have a sudden onset of growth. Psoriasis is commonly categorized as mild (covers less than 3% of the body), moderate (3%-10%), or severe (over 10%).

Genital psoriasis is rather common and usually is comparable with psoriasis found elsewhere on the body. It can be isolated to the genitalia but is frequently part of more generalized involvement. Involvement of the inguinal or crural areas is termed inverse psoriasis. Some individuals have tenderness during sexual intercourse.