Psoriasis could be divided into five types. Psoriasis vulgaris is the most common type of psoriasis. It is initially red papules or rash, then, expands gradually or merged into a flake. The surface is covered with multi-layer gray or silver white scales; Intertriginous psoriasis usually appears at the folding parts of the human body such as armpits, groin and reproductive areas, generally without any scales to be seen, the only the erythema. Guttate psoriasis usually arises in the torso among children and the onset of the disease is often related to streptococcal infection of the upper respiratory tract. Pustular psoriasis is generally seen in the palm of the hands and fingertips. The main feature of this kind is that the aggregated pustules are always filled with non-infectious pus. Erythrodermic psoriasis is the most serious type of all psoriases. It could bring about the lowering of body temperature, hypoproteinemia and high output heart failure. Generally, large areas of burn-like erythema and skin peeling are seen on the patients’ bodies.