Gallery of Photos of Psoriasis

Plaque psoriasis is the most common form of the disease, accounting for 80% to 85% of all cases. The name references the classic skin lesions that define the disease.

Round to oval in shape with clearly defined borders, the plaques most often appear on extensor surfaces. These are areas of skins on the outer side of a joint (as opposed to flexor surfaces on the inner side of a joint where the skin creases). Examples include the back of the forearm near the elbow (as pictured) and the front of the knee.

Plaque psoriasis can also develop on the scalp, neck, ears, and just above the buttocks adjacent to the lumbar spine.

The plaques tend to be more than half a centimeter (0.2 inches) in diameter and have very thick scales. Topical treatments can help clear plaques by tempering local inflammation and gently loosening the scales.

This photo illustrates how thick plaques can become if left untreated. Beyond a lack of appropriate treatment, plaque psoriasis can be instigated by any number of common and uncommon triggers. These include stress, infections, obesity, alcohol, smoking, skin trauma, medications, extreme humidity, and cold/dry weather.

Many of these—drugs and stress, especially—can exacerbate flares, making symptoms worse and more difficult to control.

In cases this severe, a doctor would likely recommend immunosuppressant drugs that temper the overactive immune response. These include disease-modifying antirheumatic drugs (DMARDs) like methotrexate and cyclosporine, or new biologic drugs like Humira (adalimumab) and Enbrel (etanercept).

The gluteal cleft (the crease of skin between the buttocks) is a common site for plaque psoriasis. This photo illustrates the characteristic plaques with their clearly defined borders and patchy scales.

The scales are one of the clues that differentiate plaque psoriasis from inverse psoriasis, which can also develop in the gluteal crease. However, with inverse psoriasis, the lesions tend to be smooth with few visible scales.

The problem with gluteal involvement is that the very act of sitting can irritate inflamed skin and make the condition worse.

In this photo, plaque psoriasis appears on the elbow and arm. There is little scaling, but the affected skin appears thick, red, and irritated. At first glance, it is easy to mistake the multiple lesions for any number of other skin conditions.

Because there are no blood tests or imaging studies that can definitively diagnose psoriasis, misdiagnosis can sometimes occur.

The diagnosis of psoriasis is based primarily on the appearance of the lesions, a review of one's medical history (including a family history of psoriasis), and the exclusion of all other causes (referred to as the differential diagnosis).

Some of the diseases and conditions that look similar to psoriasis include:

• Tinea curis (jock Itch)
• Tinea pedis (athlete's foot)
• Tinea capitis
• Seborrheic dermatitis
• Eczema
• Pityriasis rosea
• Ringworm
• Erythrasma
• Lichen planus
• Lupus
• Squamous cell carcinoma

It is not uncommon to have psoriatic plaques in areas where clothes are tight, causing friction to the skin. This picture is one such example in which pressure from a belt can give rise to a ring of psoriasis around the waist.

The phenomenon, known as the Koebner response, is associated with psoriasis and other diseases in which a rash or lesions will develop along the line of trauma.

With psoriasis, a flare may occur as a result of a cut, abrasion, sunburn, rash, or even vigorous scratching. It is even possible for psoriasis to develop on old scar tissues, including tattoos and surgical scars.

In this photo, the plaques have begun to heal. Once this is complete, the skin will often look lighter or darker than the surrounding skin. In most cases, the discoloration will normalize over time.

Guttate psoriasis is the second most common form of psoriasis, accounting or around 10% of cases, according to the National Psoriasis Foundation (NPF).

The name is derived from the Latin word gutta, which means droplet. It is characterized by small, teardrop-shaped lesions that most often develop on the trunk, but can also appear on the arms, legs, and scalp.

Because these diseases are more common in childhood, children tend to be affected by this type of psoriasis more often than adults. Adults under 30 are also vulnerable.

This picture illustrates a mild form of guttate psoriasis. The onset of symptoms is often rapid with multiple lesions erupting on the trunk and extremities in a centripetal pattern (moving from the outside in). Itchiness is common.

In addition to infections, certain drugs can trigger a flare. Among the usual suspects are beta-blockers, antimalarial drugs (like Plaquenil), and nonsteroidal anti-inflammatory drugs (especially naproxen).

This photo depicts a severe case of guttate psoriasis. As distressing as this may seem, an outbreak is usually self-limiting and will resolve on its own without treatment after several weeks or months. Some people may never experience another episode; others may develop chronic plaque psoriasis that follows them into later adulthood.

Because there are no tests to definitively diagnose guttate psoriasis, severe cases like this will typically require a battery of tests to exclude other causes (such as cutaneous T-cell carcinoma or syphilis) and to check for likely triggers (most commonly strep throat or chronic tonsillitis).