The following photographs and descriptions of the different types of psoriasis illustrate typical characteristics, but a distinguishing fact about psoriasis is its variability. It changes, over time, flaring, improving, or going into remission. It may appear on any area of the skin. One form may change to another form, or several forms may exist at the same time. Please contact your doctor if you need more complete information.

Plaque
Plaque Psoriasis is the most common type of psoriasis. The individual plaques are very red and covered with silvery-white scales. These can be very itchy and if scratched or scraped they may bleed easily. The plaques usually have a well-defined edge and, while they can appear anywhere on the body, the most commonly affected areas are the scalp, knees and elbows. The face is rarely affected. However, if the scalp is involved, you may develop psoriasis on the hairline and forehead. The actual appearance of the plaques can depend on where they are found on the body. Plaques found on the palms and soles can be scaly, however they may not be very red in colour. This is due to the thickness of the skin at these sites. If the plaques are in moist areas, such as in the creases of the armpits or between the buttocks, there is usually little or no scaling. The patches are red and have a well-defined border.

Guttate
Guttate psoriasis resembles small, red, individual drops on the skin (the word guttate comes from the Latin word meaning "drop"). These lesions generally appear on the trunk and limbs, and sometimes on the scalp, and they are usually not as thick or as scale- covered as plaque psoriasis. Guttate psoriasis often starts in childhood or young adulthood, and it may be triggered by an infection of some sort.

Inverse
Inverse psoriasis, also called flexural psoriasis, is found in the armpits, groin, under the breasts and in other skin folds around the genitals and buttocks. This type of the disease appears as smooth, dry areas of skin that are red and inflamed but do not have the scaling associated with plaque psoriasis. Inverse psoriasis is particularly subject to irritation from rubbing and sweating because of its location in skin folds and tender areas. It is more common and troublesome in overweight people.

Erythrodermic
Erythrodermic psoriasis is a particularly inflammatory form of psoriasis that often affects most of the body surface. It is the least common form of the disease. It most commonly appears on people who have unstable plaque psoriasis, where lesions are not clearly defined. The erythrodermic form of psoriasis is characterized by periodic, widespread, fiery redness of the skin. The erythma (reddening) and exfoliation (shedding) of the skin are often accompanied by severe itching and pain. Swelling may also develop. For more detailed information, click to see Reference Section listings about erythrodermic psoriasis.

Generalized Pustular
Pustular psoriasis spread over wide areas of the body is also called von Zumbusch pustular psoriasis, named after the physician who first described it in the early 1900s. In this relatively rare form of the disease, widespread areas of reddened skin (erythema) develop, and the skin becomes acutely painful and tender. Pustules—blisters of non- infectious pus—may appear on the skin, dry, then reappear in repeated cycles lasting several days.

Localized Pustular
Pustules of psoriasis can be confined to local areas, particularly the hands and feet. The form called palmo-plantar pustulosis (PPP) is characterized by large (up to .5 cm, or about the size of a pencil eraser) pustules in fleshy areas of hands and feet, such as the base of the thumb and the sides of the heels. The pustules appear in a studded pattern throughout reddened plaques of skin, then turn brown and peel. Another rare form is called acropustulosis (or acrodermatitis continua of Hallopeau). In this type, skin lesions develop on the ends of the fingers and sometimes the toes. The lesions can be painful and disabling, with nail deformities and, in severe cases, changes to the bone.