The following photos depict the different types of psoriasis, including:
Plaque psoriasisScalp psoriasisNail psoriasisGuttate psoriasisInverse psoriasisErythrodermic psoriasisPustular psoriasis
Plaque psoriasis plaques are round to oval in shape with clearly defined borders. They most often appear on extensor surfaces. These are areas of skin 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.
On people with lighter skin tones, the scales appear pink. On darker skin, they may look brown or gray. Once the scales disappear, the color of the skin where they were may be darker or lighter than it used to be.
Plaque psoriasis can also develop on the scalp, neck, ears, and just above the buttocks adjacent to the lumbar spine. There may be only a few plaques or there may be a large number of them.
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.
Psoriasis can sometimes be mistaken for eczema. You can often tell the difference between eczema and plaque psoriasis by how itchy they are, however. Eczema tends to be very itchy, while plaque psoriasis is only mildly itchy.
Plaque psoriasis is the most common form of the disease, accounting for 80% to 85% of all cases.
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
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 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.
Scalp psoriasis can also be itchy, and it can cause your scalp to become dry and cracked. In addition to scaling and flaking, your scalp may also bleed, especially if you scratch it.
If you have nail psoriasis, your nails may become thicker and you might notice a white material accumulating under them. This can cause them to separate from the skin underneath. They might even feel sore or tender to the touch.
Nail psoriasis can affect your fingernails and/or your toenails.
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.
Because the diseases that trigger guttate psoriasis 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.
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).
Because there are no tests to definitively diagnose guttate psoriasis, severe cases like this will typically require a battery of tests. These tests can help exclude other causes (such as cutaneous T-cell carcinoma or syphilis) and check for likely triggers (most commonly strep throat or chronic tonsillitis).
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Inverse psoriasis usually looks red and shiny. The lesions aren’t typically raised and they can be very sore and irritated. You probably won’t see scales in skin creases and folds because the scales tend to flake away with skin-to-skin friction.
When you have this type of psoriasis, your skin may peel off in large sheets and you may also develop fluid-filled blisters. Other symptoms include:
Fever and chillsJoint painRapid heartbeatSwelling in the legs and anklesIrregular body temperature
Pustular psoriasis may affect only small parts of the body, such as the palms or soles of the feet. This type is known as palmoplantar pustulosis. The second type, called acrodermatitis continua of Hallopeau, causes tiny, painful pustules on the fingertips and toes, which may spread to the hands or soles of the feet.
Von Zumbusch psoriasis is the most serious type of pustular psoriasis. People with this type will experience pustules over a large part of the body. Additional symptoms may include:
Fever and chillsHeadacheNauseaMuscle weaknessJoint painFatigue
People with Von Zumbusch psoriasis need to seek medical care immediately to avoid more serious complications like dehydration and an increased risk of infection.
The two most common types of psoriasis are plaque psoriasis and guttate psoriasis. If you think you might have symptoms of psoriasis, see your healthcare provider.
