Which type do you have?

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Psoriasis vulgaris (plaque psoriasis)

Psoriasis vulgaris

Psoriasis vulgaris, also known as “plaque psoriasis,” is the most common form of psoriasis and affects 90% of people with the disease. Psoriasis vulgaris appears as dry, slightly elevated, red patches, known as plaques, which are covered with a layer of silvery white scales. They tend to start out as small bumps that grow together and are typically found on the elbows, knees, scalp and buttocks.

If you have plaque psoriasis, you may also experience changes to your toenails and fingernails – in fact, this occurs in about half of people with psoriasis. There are four changes to be aware of: pitting, thickening, discoloration and loosening of the nail from the nail bed.

Although the cause of plaque psoriasis is unknown, it is believed that hereditary factors, environmental factors and the immune system all play important roles.

There are a variety of treatments for plaque psoriasis. Some are available over the counter at your local drugstore; others are available only by prescription. Unfortunately, no one treatment works for everyone. The best approach is to talk to your dermatologist about your treatment options, and then you and your dermatologist can decide together which one may be right for you.

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Plaque psoriasis of the scalp

Plaque psoriasis
of the scalp

Plaque psoriasis of the scalp is one of the more common forms of the disease, affecting at least half of all people who have psoriasis. Plaques appear on the scalp and may spread to the ears, forehead and the back of the neck. Hair loss may result in severe cases where the entire scalp is covered. Plaque psoriasis of the scalp can occur without the appearance of plaques on the rest of the body.

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Guttate psoriasis

Guttate psoriasis

Guttate psoriasis appears as small, pinkish dots that can spread to cover large areas of the upper body, legs and arms. This type of psoriasis commonly appears in adolescence. It often occurs suddenly and sometimes in response to a respiratory infection such as a streptococcal infection (“strep throat”).

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Pustular psoriasis

Pustular psoriasis

Pustular psoriasis appears as small, white, fluid-filled blisters (pustules) surrounded by swollen, reddish skin. It tends to appear primarily on the palms and soles of the feet. While these localized lesions are difficult to treat, they pose no real threat to the body. However, pustular psoriasis that covers the entire body can result in fever, fluid imbalances and infection. The majority of people with the more generalized form of this psoriasis need to be hospitalized.

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Palmo-plantar pustulosis

Palmo-plantar
pustulosis

One type of pustular psoriasis is known as palmo-plantar pustulosis. Small pustules form on the palms of the hands and the soles of the feet. The pustules appear within the plaques and eventually turn a brownish colour, peel and develop a crusty surface.

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Inverse psoriasis

This form of psoriasis appears in the folds of the skin as smooth, red, dry patches without the scale found in plaque psoriasis. It may also be accompanied by itching. Inverse psoriasis may appear in the genital area as well as under the breasts and in the armpits.

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Erythrodermic psoriasis

Erythrodermic psoriasis

This form of psoriasis occurs sporadically, often covering almost the entire body. The skin appears bright red with extensive scaling. It can be quite painful and severe itching may also be present.

Because symptoms are widespread over the body, this form can be extremely serious. If you have a flare-up of this type of psoriasis, you should see your doctor immediately. The resulting protein, fluid loss, and decrease in body temperature can lead to severe, life-threatening illness and may require hospitalization.

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Psoriasis of the nails

Psoriasis
of the nails

Psoriasis affects the fingernails in 50% of people with psoriasis, and the toenails in 35%. Nail changes vary, but the most common are:

• Severe thickening of the nail
• Shallow or deep holes (pits) in the nail
• Nail discoloration, such as yellow-brown
• Nail separation from the nail bed

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Psoriatic arthritis: a related condition

Seven to 42% of people with psoriasis have psoriatic arthritis, an inflammatory disease that affects both the skin and the joints. Skin symptoms usually appear before the joint symptoms which typically affect the tendons and ligaments surrounding the bones of the knees, lower back, fingers, toes or a number of other joints. The "hinge" joints of the hands and feet may also become swollen and stiff, taking on a sausage-like appearance and resulting in tendonitis.

While the skin symptoms and the joint symptoms frequently appear at different times, often years apart, psoriasis is usually diagnosed first. The skin lesions have a distinct, raised border and are bright red and covered in a silvery white scale. Other symptoms may include pitting and ridges in the fingernails and toenails. Both dermatologists and rheumatologists (doctors who specialize in joint disease) treat psoriatic arthritis; however, each focuses on different aspects of the disease. Dermatologists focus primarily on evaluating and treating disorders of the skin, nails and hair. Rheumatologists specialize in treating patients with arthritis.