5 Different Types of Psoriasis

There are five types of psoriasis, and although most people have only one type at a time, it’s not unheard of to have more than one. It is also possible for one type to convert to another; this usually occurs because of an outside trigger, such as abruptly stopping a medication.

Plaque Psoriasis

The most common form of psoriasis is plaque psoriasis, or psoriasis vulgaris — approximately 80 percent of people with psoriasis have this type. It is characterized by hard, red, raised patches on the skin that have a silvery white, scaly coating. These well-defined patches are referred to as plaques, and they usually start as small red bumps. Plaques can remain as separate, isolated areas or join together to form a larger plaque; they appear most often on the elbows, knees, and lower back, although they can appear anywhere on the body, including the scalp. It is rare, however, to see this type of psoriasis on the face. Plaques can last for months or years and can appear — and disappear — for no known reason.

Guttate Psoriasis

The second most common type of psoriasis, guttate psoriasis, is characterized by widespread small, red (sometimes teardrop-shaped) spots on the skin. Most common in children and younger adults, the spots come on suddenly, quite often after some kind of bacterial or viral infection, and usually appear across the trunk and on the limbs. While some cases of guttate psoriasis are severe, requiring oral medication or injections, milder cases can clear up without treatment and never recur. This type of psoriasis can also begin as plaque psoriasis and convert because of a medical trigger, such as chicken pox, strep throat, or a skin injury.

Pustular Psoriasis

Pustular psoriasis is rare, occurring in less than 5 percent of people afflicted with psoriasis. It is characterized by raised, pus-filled bumps (pustules) on the skin. The pustules can appear within hours after the skin’s surface becomes red and itchy; they occur in waves, scaling and healing in a few days and then reappearing. Pustular psoriasis can be generalized and widespread across the body or localized to the palms of the hands and the soles of the feet (palmar-plantar pustulosis). Generalized pustular psoriasis can lead to fever, anemia, and other life-threatening conditions and often requires hospitalization. Both forms occur mainly in adults and can be triggered by certain medications (including lithium and cortisone), by pregnancy, and by infections like strep throat. Stopping certain medications suddenly (including steroid medications) can also trigger a flare of pustular psoriasis.

Inverse Psoriasis

Inverse psoriasis (also known as flexural psoriasis) occurs in the folds of the skin, such as those found in the armpits and groin and under the breasts. While uncommon overall (only 2 to 6 percent of psoriasis sufferers have this type), inverse psoriasis is most prevalent in people who are overweight, and it’s aggravated by friction and sweating. Appearing as smooth, sometimes shiny patches rather than the scaly lesions seen in other types of psoriasis, areas affected by inverse psoriasis are red, inflamed, and tender. Because the sites typically involved are prone to yeast and fungal infections, this type of psoriasis can sometimes be confused with candida.

Erythrodermic Psoriasis

Only 1 to 2 percent of people with psoriasis have erythrodermic psoriasis, which may occur in conjunction with pustular psoriasis or on its own and is characterized by a scaly, red, and inflamed rash over the entire body or most of it. Itchy and often extremely painful, erythrodermic psoriasis can be fatal, and it is imperative that it be monitored closely. In severe cases, hospitalization may be necessary because the skin loses its ability to regulate temperature and perform normal barrier functions. This can cause life-threatening dehydration, fever, and infection. Erythrodermic psoriasis is usually treated with topical and systemic medications.

While not considered a distinctive type of psoriasis, psoriatic arthritis occurs in about 10 to 35 percent of psoriasis patients; in most cases, skin symptoms appear before the arthritis, which can sometimes cause debilitating inflammation of the hands, knuckles, knees, and ankles.

So What Is Psoriasis, Exactly?

Psoriasis is a chronic disease that develops when a person’s skin cells grow too quickly (they form in a few days rather than weeks) due to faulty signals from the immune system. The body doesn’t shed these cells, so they pile up on the surface of the skin, which causes patches of psoriasis to appear.
“Normal skin cells will mature over about a period of two months and shedding will happen over three months. Psoriasis skin cells can mature in about five days,” says Dr. Friedler.

Symptoms of Psoriasis

The symptoms of psoriasis depend on the type of psoriasis you have. There are five main different types of psoriasis: plaque, guttate, inverse, pustular, and erythrodermic. These different types can appear alone, or with another type.

The most common type is plaque psoriasis. “Psoriasis plaques are often red and have very thick, oyster-like scale on them. This can be uncomfortable and they can also be emotionally debilitating to patients,” says Dr. Friedler.

Signs of plaque psoriasis include:

  • Red, flaky, and sometimes itchy skin
  • Patches that are covered with a silvery-white coating, which dermatologists call scale
  • Itchy patches that thicken when scratched
  • Nail problems—pits in the nails, crumbling nail, nail falls off

The most common locations on the body for psoriasis to appear are elbows, knees, the belly button, the crease of the buttocks, and sometimes the scalp. Psoriasis can also appear in the body folds, like under the arms and in the groin folds, which is called inverse psoriasis.

How to Treat Psoriasis

The first step to getting the appropriate treatment is being able to differentiate psoriasis from other skin conditions, and getting properly diagnosed by a dermatologist. “Psoriasis treatment is different than treatment for other rashes, so getting the correct diagnosis from your dermatologist is important in ascertaining that you get the right therapies,” says Dr. Friedler.

Even though psoriasis can’t be cured, there are plenty of lifestyle adjustments that help psoriasis symptoms—like eating a psoriasis-friendly diet, relieving stress, and avoiding habits that can cause psoriasis flare-ups—and medications available that may not only help clear a patient’s skin (sometimes close to completely), but can also significantly improve their quality of life.

“Psoriasis has had an explosion of new therapies over the last few years and this has been providing great hope for patients who’ve been suffering with psoriasis,” says Dr. Friedler. “These new medication classes have also had a profound effect on patients affected by psoriatic arthritis by helping protect their joints and helping prevent progression of that debilitating disease.”


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