Psoriasis

Psoriasis is a long-lasting condition that affects the skin, but it cannot spread from one person to another. People with psoriasis have patches of abnormal skin that are red, pink, or purple, dry, itchy, and scaly. These patches can be small and localized or cover large areas of the body. Injury to the skin can sometimes cause new patches to appear at that spot.

There are several types of psoriasis, including plaque, guttate, inverse, pustular, and erythrodermic. Plaque psoriasis is the most common, showing red patches with white scales, often on the arms, legs, belly area, or scalp. Other types can cause drop-shaped spots, red patches in skin folds, small pus-filled blisters, or very widespread rash. Psoriasis can also affect fingernails and toenails, causing pits or color changes.

Psoriasis is believed to be caused by a combination of genetic and environmental factors. It often gets worse during winter or with certain medications, infections, or stress. The immune system plays a key role in the development of the condition. While there is no cure, treatments like steroid creams, vitamin D cream, ultraviolet light therapy, and certain drugs can help control the symptoms. The condition affects about 2–4% of the population and can sometimes be linked to other health issues.

Signs and symptoms

Psoriasis is a common skin condition that causes red, itchy patches covered with silvery scales. The most frequent type is called plaque psoriasis, which often appears on the elbows, knees, scalp, and back. These patches can be raised and may feel inflamed.

Other types of psoriasis include pustular psoriasis, which shows small bumps filled with pus, and inverse psoriasis, which affects skin folds like armpits and groin areas. There are also forms that appear in infants, on the scalp, or inside the mouth. Psoriasis can also affect the nails, causing changes like pitting, discoloration, or thickening. Sometimes, it can even cause joint pain, known as psoriatic arthritis.

Causes

The exact reason for psoriasis isn't completely known. It seems that family history, changes in the seasons, damage to the skin, climate, certain infections, and some medicines can all play a role in causing different kinds of psoriasis.

Many people with psoriasis have family members who also have the condition, suggesting that genes are important. Studies with identical twins show that if one twin has psoriasis, there is a high chance the other will too. Researchers have found several genes linked to psoriasis, especially those involved in the immune system. These genes can influence how the body’s defenses react, sometimes leading to skin changes.

Other factors that might make psoriasis worse include stress, infections, changes in temperature, hot water, scratching the affected skin, very dry skin, drinking too much alcohol, smoking, and being overweight. Sometimes, certain medicines can also trigger or worsen psoriasis.

Pathophysiology

Psoriasis happens when the skin grows too quickly. Normally, skin cells grow and replace themselves in about four weeks, but in psoriasis, they grow and replace themselves in just a few days. This rapid growth causes red, scaly patches on the skin.

This fast growth is caused by the body’s immune system acting in a way that makes the skin inflamed. Certain cells in the immune system send out chemical signals that tell skin cells to grow faster. Scientists think that changes in genes may also play a role in making someone more likely to develop psoriasis.

Diagnosis

A diagnosis of psoriasis is usually made by looking at the skin. The skin will have scaly, red patches that may be painful and itchy. Usually, no special blood tests or other tests are needed to diagnose psoriasis.

If it is not clear what is causing the skin problems, a small piece of skin may be taken to look at under a microscope. This helps to make sure it is psoriasis and not something else. There are other skin conditions that can look similar to psoriasis.

Co-morbidities

Psoriasis is not just a skin condition. It can also affect a person's overall well-being. Managing psoriasis can be challenging because it may bring extra health and financial concerns.

People with psoriasis may have a higher chance of heart-related health issues, such as heart attacks and strokes. This may be linked to ongoing inflammation in the body.

Depression is also more common among people with psoriasis. The visible changes to the skin can lead to feelings of being judged, which can affect mood. Other factors related to the immune system might also play a role.

Additionally, psoriasis can increase the risk of developing type 2 diabetes. Studies have shown that certain genes linked to both conditions might be involved in these health challenges.

Management

While there is no cure for psoriasis, there are many ways to help manage it. For mild cases, doctors often use special creams or ointments applied to the skin. For more serious cases, treatments like controlled exposure to sunlight or stronger medicines might be needed.

Some of the most common treatments include creams with ingredients that calm the skin, like certain types of vitamins. For psoriasis on the scalp, combining different creams often works best. Keeping the skin moisturized with oils or special lotions can also help reduce redness and scaling.

For more severe psoriasis, doctors might suggest treatments that use controlled sunlight or special light therapy. These can help slow down the growth of affected skin cells. In some cases, doctors may also prescribe medicines that are taken by mouth or injected to help control the condition. These treatments need careful monitoring because they can affect the whole body.

Lifestyle changes, like eating certain types of food and avoiding others, might also help some people feel better. For example, eating more fish rich in omega-3 fatty acids, like salmon, and less red meat or sugary foods, can sometimes improve symptoms. However, what works best can vary from person to person.

Prognosis

Most people with psoriasis have mild skin patches that can be treated well with creams. Depending on how bad the patches are and where they appear, some people may feel uncomfortable, especially if the patches are on their hands, feet, or scalp. This can make daily activities, sleeping, or even playing sports harder.

People with psoriasis might feel worried about how their skin looks, which can affect their confidence. They may also feel left out or treated differently because some people think psoriasis is contagious, which it is not. This can lead to feelings of sadness or being lonely. Some children with psoriasis might face teasing from others.

Psoriasis is also linked to other health issues, especially in older adults. These can include problems with the heart and metabolism. People with psoriasis may have a higher chance of developing diabetes, high blood pressure, and other heart-related conditions. There are also links to other diseases, such as Crohn’s disease and ulcerative colitis. Some treatments for psoriasis can affect cancer risk, but this is usually linked to the medicines used rather than the disease itself.

Epidemiology

Psoriasis is estimated to affect 2–4% of people in the Western world. It appears more often in some groups than others. It is more common in people of European descent than in people of Asian descent, and it is less common in African Americans and very uncommon in Native Americans. About 6.7 million Americans have psoriasis.

Psoriasis can appear at any age, but it most often starts between the ages of 15 and 25. About one-third of people with psoriasis are diagnosed before they turn 20. It affects both males and females equally. People with certain health conditions, like Crohn’s disease or ulcerative colitis, have a higher chance of developing psoriasis.

History

People have talked about psoriasis for a very long time. Some scholars think it might have been one of the skin problems called tzaraath in the Hebrew Bible. The Greeks used different names for skin issues, like lepra for scaly skin and psora for itchy skin. In the late 1700s, a doctor named Robert Willan helped make it clear that psoriasis is different from other skin diseases.

Doctors have tried many different ways to treat psoriasis over the years. Some old treatments were not safe and could even make people sick. Even famous people like Admiral William Halsey had to stop fighting in World War II because of psoriasis. Today, we know much more about how to help people with this condition.

Society and culture

Psoriasis affects many people around the world, and there are groups that help support and educate them. Organizations like the International Federation of Psoriasis Associations bring together experts and caregivers to share knowledge and help improve care. Countries also have their own groups, such as the National Psoriasis Foundation in the United States and the Psoriasis Association in the United Kingdom. Each year on October 29, World Psoriasis Day is celebrated to raise awareness.

Cost

Treating psoriasis can be expensive. In the United States, the cost of care is very high, with many resources used for medications. These costs become even higher when people have other health problems at the same time.

Research

Scientists are studying how the body’s handling of insulin relates to psoriasis. Early studies show that certain natural substances might help reduce the redness and swelling linked to psoriasis.

Researchers in the 2010s looked into new medicines that target specific parts of the body’s defense system. These medicines aim to calm the activity that leads to psoriasis. Other studies explored different treatments, including pills taken by mouth instead of injections, which have shown promise in tests but can sometimes have serious effects on the body’s defenses.