WebMD explains the itchy, red, scaly skin condition called psoriasis and who is likely to get it. Symptoms, causes, and treatments are covered with pictures. My Account Sign Out WebMD: Better information. Better health. MedicineNet does not provide medical advice, diagnosis or treatment. Dermatology Pictures – Skin Disease Photos. Additional information:.
Theories about the causes of psoriasis need to explain why the skin is red, inflamed and thickened. The plaques are usually very persistent without treatment. Psoriasis. Psoriasis is a skin disease that causes itchy or sore patches of thick, red skin with silvery scales. Sometimes psoriatic plaques are itchy but usually when you have guttate psoriasis they do not itch. Guttate psoriasis treatment is quite complicated.