Psoriasis is a chronic immune disorder, which causes itchy, painful plaques to develop on the skin. The psoriasis rash can develop anywhere on the body, including the chest. As the rash progresses, bumps on the chest may grow larger, and red and violet plaques with silvery scales may develop.

Psoriasis is not contagious, meaning a person with the condition cannot pass it to another individual. It is a systemic condition, meaning it affects the body from the inside.

This article explores psoriasis, including types and symptoms. It also looks at diagnosis and treatment.

Psoriasis is an immune-mediated disease, meaning the condition is due to inflammation brought about by a dysfunctional immune system. Visible signs of inflammation often include scales or raised plaques.

The overactive immune system speeds up the growth of cells. While skin cells normally shed within a month, psoriasis causes skin cells to grow faster, doing this in only 3–4 days. This rapid growth means that shedding is ineffective, and the skin cells pile up on top of each other, causing plaques and scales. The condition may cause a feeling of burning, itching, or stinging.

Psoriasis can develop anywhere on the skin, including the chest, but most commonly occurs on the knees, scalp, and elbows.

What does psoriasis look like?

Psoriasis presents differently on other skin colors than on white skin. The condition is more common in white people, with around 3.6% of white people in the United States affected by psoriasis compared to 1.9% of African American and Hispanic American people.

While white people with psoriasis typically experience red, scaly plaques, people of color experience discoloration that is darker, and the skin may become thicker. The skin can present as violet, darker brown, or gray color rather than red. Because of this, psoriasis may go misdiagnosed and undiagnosed more frequently among people of color.

The condition is also often more serious in people of color. Studies have found that Asian and Hispanic people experience psoriasis more severely than white people.

With this in mind, researchers need to conduct more studies on how psoriasis affects the skin of people of color, especially in Black people, as most research features white patients.

Psoriasis is often associated with or mistaken for other conditions. These include:

  • Eczema: Doctors sometimes misdiagnose psoriasis as eczema. An Australian study found that most children with psoriasis were initially diagnosed by their doctors as having eczema. In some cases, individuals develop both psoriasis and eczema, so there can be some overlap of conditions. A dermatologist will generally be able to differentiate between these two health issues.
  • Ringworm: This is a fungal infection called tinea or dermatophytosis. People refer to it as ringworm because it can cause a ring-shaped rash, which is usually red and itchy.
  • Pityriasis rosea: This condition causes a rash that often starts as a large oval patch on the skin, followed by smaller patches or small bumps. The rash can appear anywhere on the skin and is common on the chest, stomach, and back. It may accompany flu-like symptoms and itching.
  • Shingles: A painful rash that generally occurs on only one side of the body or face. It develops into blisters that usually scab over within 7–10 days.

People with psoriasis are more likely to have some other disorders, including:

There are various types of psoriasis, including:

Guttate psoriasis

This is the type of psoriasis most likely to appear on the chest, developing as small, round, red spots that result from inflammation. Guttate psoriasis affects about 8% of people with the condition.

Chronic plaque psoriasis

Plaque psoriasis is the most common type and affects up to 80% of those with the condition. The plaques can appear anywhere on the body, including the chest. They present as raised, inflamed patches of skin, which may be red or violet with silvery scales, and they can be itchy and painful.

Inverse psoriasis

This type of psoriasis affects about 25% of people, and most commonly develops in the folds of skin, in areas such as under the breasts, the genital area, and underarms. Inverse psoriasis usually presents as inflamed, dark red skin. While it does not cause scales or plaques, it can be painful and itchy.

Pustular psoriasis

This type affects about 3% of people with psoriasis. Symptoms include inflamed, red skin and white, pus-filled, painful bumps. It may cover most of the body or appear on certain areas such as the feet and hands.

Erythrodermic psoriasis

This type of psoriasis is rare, affecting around 2% of people with the condition. It is severe and can cause intense redness and shedding of skin, which comes off in large sheets. It can affect the entire body and can be life threatening. Other symptoms include changes in temperature and heart rate, severe pain and itching, and dehydration.

The symptoms of psoriasis stem from inflammation. They can vary from person to person but may include:

  • patchy thick skin that is red or darker in color, with silvery scales that itch or burn
  • cracked, dry skin that bleeds or itches
  • thick, ridged nails.

Psoriasis symptoms tend to flare up and then calm down. People with the condition may have times where symptoms worsen and then ease off, where they feel better.

Doctors do not fully understand what triggers psoriasis, but it has several associations, including the below.

Family history

A person has a higher risk of developing psoriasis if they have a parent, grandparent, or sibling with psoriasis.

Immune system

When a person has psoriasis, their white blood cells malfunction. White blood cells normally attack viruses and bacteria, but the condition causes them to attack the skin, causing the body to make more new skin cells faster than usual. The extra skin cells pile up on the surface of the skin.

Once this condition starts, it usually continues for the rest of a person’s life, becoming chronic.

Triggers

Common triggers for psoriasis include:

  • skin injury, such as sunburn
  • stress
  • some medication, including hydroxychloroquine and lithium
  • infection, such as strep throat
  • cold, dry weather
  • tobacco
  • alcohol

A dermatologist will diagnose psoriasis by examining a person’s scalp, nails, and skin for signs of the condition. They will ask for any symptoms of the condition, including itchy skin, joint problems, or a family history of psoriasis.

Sometimes, a dermatologist may perform a biopsy by removing a piece of the skin. By examining this sample, they can confirm whether or not a person has psoriasis.

A dermatologist will treat psoriasis according to the severity of the condition and its location on the body. For psoriasis on the chest, a person may receive topical medication to apply directly to the skin, medications that work throughout the body, or light therapy. These medications may include corticosteroids, synthetic vitamin D, retinoids, and coal tar. Light therapy, or phototherapy, involves a doctor or dermatologist shining UV light onto the skin.

A person can make changes to their diet, which may help improve psoriasis. Foods that have an anti-inflammatory effect include:

  • fiber
  • nuts and seeds
  • oily fish
  • vegetables
  • fruits
  • beans

Psoriasis is a chronic immune disorder that triggers inflammation. It can occur anywhere on the body, including the chest. While people of color may experience psoriasis more severely than white people, more research needs to focus on the effects of psoriasis on the skin of people of color.

Different types of psoriasis include plaque, guttate, inverse, pustular, and erythrodermic, while symptoms include patchy, dry, cracked, and scaly skin. Psoriasis may be due to genetics, the immune system, and certain triggers, such as dry weather. Treatment may include medication, phototherapy, or dietary changes.