Psoriasis vulgaris is the most common form of psoriasis. Vulgaris is Latin for “common,” so it means a common form of psoriasis. The type of psoriasis that affects the most people is plaque psoriasis. As with all types of psoriasis, plaque psoriasis is not contagious.

Psoriasis affects over 7.5 million adults in the United States. Plaque psoriasis affects between 80–90% of people who have psoriasis experiencing this type. It is a chronic condition, which means that they may need ongoing medical attention. Psoriasis symptoms may also come and go in flare-ups.

This article will explain what plaque psoriasis is and what it looks like. It will also look briefly at other types of psoriasis before explaining treatment options.

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Psoriasis is an autoimmune condition that affects the skin. It affects over 3% of the adult population of the U.S. In people with plaque psoriasis, the skin cells form quicker than in their typical life cycle, which makes them build up. This causes raised, scale-like areas to develop.

A number of factors can trigger psoriasis, including:

  • certain foods
  • smoking
  • stress
  • injury to the skin
  • some medications
  • infection

Psoriasis scales are not contagious. But they can be itchy and painful. Some people may find these symptoms disrupt their everyday life.

Learn more about psoriasis triggers here.

Psoriasis vulgaris causes plaques, or scales, to form. These are patches of inflamed, silvery skin that usually occur on the:

According to the National Psoriasis Foundation, plaques typically affect the same body parts on both the right and left side of a person’s body. They also indicate that some people with psoriasis vulgaris experience itchiness, burning, and stinging in the areas that have developed plaques.

The appearance of the scales varies depending on a person’s skin color.

  • Light skin: The skin may become red, or pink, with a silvery-white scale.
  • Brown skin: A silvery-white scale may appear alongside coral-colored skin.
  • Black skin: The scales on this complexion may appear gray, and the surrounding skin may become purplish or appear darker.

Lighter or darker patches of skin may appear on skin of color. This is known as “dyspigmentation”. Dyspigmentation is temporary but may take a long time to resolve. Some people choose to have treatments to lighten or darken their skin in certain cases.

See pictures of psoriasis on black skin here.

Although plaque psoriasis is the most common form of psoriasis, there are many other types.

These include:

  • Guttate psoriasis: The main characteristic of this condition is small, scaly patches that look like raised red droplets on the skin. They often appear on the arms, legs, and torso, but can also develop on the face, ears, and scalp. It is likely to be more itchy than plaque psoriasis. Guttate psoriasis affects around 8% of people with psoriasis.
  • Inverse psoriasis: This affects between 3–7% of people with psoriasis. It is where red patches develop in the folds of the body, such as under the armpit or in the groin region. It occurs where skin touches skin. While psoriasis vulgaris patches are scaly, inverse psoriasis patches are smooth and shiny.
  • Erythrodermic psoriasis: An itchy and burning rash covers the entire body. It is one of the most serious forms of psoriasis.
  • Palmoplantar psoriasis (localized pustular psoriasis): Painful, pus-filled blisters develop on the hands and feet, as well as thick, scaly skin that may crack easily.
  • Psoriatic arthritis: This is where psoriasis begins to affect a person’s joints as well as their skin. It is a common complication of other forms of psoriasis. It can eventually affect 10–20% of people with psoriasis.
  • Generalized pustular psoriasis: In this rare form of psoriasis, small pustules develop over a short amount of time, merge together and then dry out and peel. More pustules form on the same areas, and the cycle continues every few days or weeks.
  • Nail psoriasis: This is where the fingernails and toenails become thick or brittle, or peel. They may also peel off. According to the American Academy of Dermatology Association, most people who have plaque psoriasis develop nail psoriasis.

Treatment for psoriasis vulgaris depends on how severe the condition is, but is the same for skin of all colors. Doctors typically classify psoriasis as mild, moderate, or severe:

  • Mild: During a flare-up, plaques appear on less than 2% of the body.
  • Moderate: 3–10% of the body has plaques.
  • Severe: In people with severe psoriasis, 10% or more of their skin develops plaques.

Learn more about severe psoriasis here.

Medical treatment

There are a variety of different medical treatment options that a person may want to discuss with their doctor.

These include:

  • Topicals: A doctor may prescribe topical steroids to reduce the swelling and redness associated with plaques. They may also prescribe nonsteroidal treatments, such as those including synthetic vitamin D3 and vitamin A. Some over-the-counter (OTC) medication, such as coal tar, can help treat mild psoriasis.
  • Systemics: These are prescription medications that work on psoriasis from the inside out. A person can take these orally in liquid or pill form, or by injection or infusion.
  • Phototherapy: This involves exposing a person’s skin to UV light under medical supervision. This requires regular, consistent treatments and can either take place at a specialist clinic or at home.

Learn about home phototherapy for psoriasis here.

At-home treatment

There are many things a person can do at home to try and help prevent flare-ups of psoriasis vulgaris.

These include:

  • using OTC corticosteroid creams
  • avoiding foods and alcohol that can cause flare-ups
  • stopping smoking
  • using a humidifier to help prevent the air from being too dry, therefore drying out the skin
  • lowering stress levels where possible
  • trying complementary therapies such as acupuncture, although there is no clinical evidence to support its effectiveness

Learn about home remedies for psoriasis here.

The term psoriasis vulgaris refers to the most common form of psoriasis, which is plaque psoriasis. It is not curable. But it is very treatable, meaning a person can reduce the severity and frequency of flare-ups with the correct treatment.

People who think they have psoriasis vulgaris should seek medical attention to confirm the diagnosis. They can then begin treatment as soon as possible.