There are five main types of psoriasis and a few rarer types of psoriasis, each with a unique appearance and set of symptoms. Usually, a person has only one type of psoriasis at a time. Let’s take a look at the five kinds of psoriasis.
- Plaque-type psoriasis. This is the most common type of psoriasis, affecting 80-90 percent of all people who have psoriasis. Plaque psoriasis involves several areas of the skin involved with raised areas of skin which is inflamed due to the autoimmune aspect of the disease. There is a silvery, white covering on top of the redness, which represents thick pile-ups of skin cells. The areas of skin involved are called “plaques”. Plaque-type psoriasis can occur on any part of the body but most commonly occurs on the extensor side of the arms and legs, such as on the elbows and outer knee. The plaques may or may not itch and become inflamed when a sufferer scratches the plaque. This inflammation of the plaque is called the Koebner phenomenon.
- Guttate Psoriasis. This type of psoriasis involves numerous round, small spots occurring over large areas of the body, such as the trunk, the scalp and the limbs. It looks a lot like the temporary infection of the skin called pityriasis rosea. This kind of psoriasis appears to be related to having a streptococcal throat infection. Primarily children and young adults are affected by this type of psoriasis. It comes on suddenly and usually several weeks after having had a streptococcal infection. Other stressors that can bring on guttate psoriasis include upper respiratory infections, tonsillitis, stress, injury to the skin and the administration of certain drugs including antimalarials and beta-blockers. Guttate psoriasis may go away on its own or doctors can use antibiotics to treat this form of psoriasis. If you have guttate psoriasis, you may not get it back again (have a flare up) for a very long time.
- Inverse Psoriasis. This type of psoriasis is called “inverse” because it occurs on the inner surfaces of the arms and legs and in the folds of the skin rather than on the external surface of the knees or elbows. It is also called flexural psoriasis. The affected areas of skin are smoother than with plaque psoriasis and skin folds are primarily affected, especially beneath the breasts and in the creases around the genitals. It can also occur in the armpits and beneath the fold of skin in overweight people who have an abdominal skin fold (called a pannus). Friction and sweat make this kind of psoriasis worse and one can easily get secondary yeast infections from this type of psoriasis.
- Erythrodermic Psoriasis. Erythrodermic psoriasis is a serious and sometimes fatal form of psoriasis involving widespread inflammation and sloughing off of damaged skin. There can be serious itching, swelling of the skin area and pain in the affected areas. It can occur as a worsening of regular plaque psoriasis, especially if treatment is abruptly withdrawn. The extreme involvement of the skin affects the ability of the body to regulate its temperature and the barrier function of the skin is lost so that severe secondary infections can result.
- Pustular psoriasis. This form of psoriasis looks like raised bumps on the skin that are filled with pus that is not infectious. The skin beneath the pustules is inflamed, red and sore. One can get a localized spread of pustules, such as on the hands or feet, or one can get a generalized form of pustular psoriasis, involving big patches of skin on just about any body part. There are many types of pustular psoriasis as you’ll see below. Pustular psoriasis is extremely rare and can be severe enough that the patient needs to be hospitalized. It can be especially debilitating when it affects the soles of the feet or the palms of the hand. Fever and chills can be a common occurrence with this form of psoriasis.