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DermNet NZ


Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z



Plaque psoriasis

What is plaque psoriasis?

Plaque psoriasis is the most common presentation of psoriasis. It presents as small to large, well demarcated, red, scaly and thickened areas of skin. It most likely to affect elbows, knees, and lower back but may arise on any part of the body.

It tends to be a relatively persistent or chronic pattern of psoriasis that can be improved with treatment but is difficult to clear completely with topical treatments alone. It is characterised by large flat areas (plaques) of psoriasis with typical silvery scale. These plaques may join together to involve very extensive areas of the skin particularly on the trunk and limbs. It is often accompanied by scalp and nail psoriasis.

Types of chronic plaque psoriasis

Most cases of plaque psoriasis are described as 'large plaque' or 'small plaque' psoriasis. The plaques may be localised (e.g. to elbows and knees) or generalised (involving scalp, trunk and limbs).

Large plaque psoriasis

Large plaque psoriasis describes thick, well-demarcated, red plaques with silvery scale. This type of psoriasis often has early onset (<40 years) and may be associated with metabolic syndrome. There's often a family history of psoriasis. It can be quite resistant to treatment.

Large plaque psoriasis Large plaque psoriasis Large plaque psoriasis
Large plaque psoriasis

Small plaque psoriasis

Small plaque psoriasis often presents with numerous lesions a few millimetres to a few centimetres in diameter. The plaques are thinner, pinkish in colour and have a fine scale. They may be well-defined or merge with surrounding skin. Family history is less common. Although it may arise at any age, small plaque psoriasis often arises in those over than 40 years of age. This type of psoriasis often responds well to phototherapy.

Small plaque psoriasis Small plaque psoriasis Small plaque psoriasis
Small plaque psoriasis

Other types of plaque psoriasis

Uncommon subtypes or descriptions of chronic plaque psoriasis include:

Lichenified psoriasis
Lichenified psoriasis
Ostraceous psoriasis
Ostraceous psoriasis
Elephantine psoriasis
Elephantine psoriasis
Linear psoriasis following the lines of Blaschko
Linear psoriasis
following lines of Blaschko
Koebnerised psoriasis following shingles
Koebnerised psoriasis
following shingles
Photosensitive and koebnerised plaque psoriasis arising after mild sunburn
Photosensitive psoriasis
following mild sunburn
Uncommon forms of plaque psoriasis

More images of plaque psoriasis ...

Assessment of plaque psoriasis

Patients with chronic plaque psoriasis should be assessed by a dermatologist. Factors considered may include the following.

Patients to be treated with systemic therapy will be asked to undertake screening tests to ensure the medication is safe for them and as a baseline.

Treatment of chronic plaque psoriasis

Localised or mild chronic plaque psoriasis is usually managed initially with one or more topical agents. The following agents are usually effective for plaque psoriasis:

If plaque psoriasis is too extensive or severe to be effectively managed with topical treatments alone, phototherapy or systemic agents can be used and are usually very effective at improving and even clearing the psoriasis. For more information on these and other treatments, see DermNet's page on treatment for psoriasis.

Related information

References:

On DermNet NZ:

Other websites:

Books about skin diseases:

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Author: Dr Amy Stanway, Department of Dermatology, Health Waikato

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If you have any concerns with your skin or its treatment, see a dermatologist for advice.