The exact cause of psoriasis is unknown, but it likely results from a combination of genetic and environmental factors. Having another autoimmune disorder or taking certain medications may raise the risk.

Psoriasis is an autoimmune disorder that affects the skin. It causes skin cells to multiply rapidly and accumulate on the surface of the skin. These extra skin cells create thick, scaly patches called plaques.

While the specific causes of psoriasis aren’t completely understood, researchers have theories about why psoriasis develops, including specific genes and environmental triggers.

Keep reading to learn about the possible causes and triggers for psoriasis.

Scientists don’t fully understand what causes psoriasis to develop.

Scientists have identified about 80 gene variants that can increase your risk for psoriasis. These genetic variants are believed to cause changes in the way the body’s T cells behave. T cells are immune system cells that normally target harmful foreign bodies, such as viruses and bacteria.

In people with psoriasis, T cells also attack healthy skin cells by mistake. This immune system response results in a range of reactions, including:

  • the enlargement of blood vessels in the skin
  • an increase in white blood cells that stimulate the skin to produce new cells more quickly than usual
  • an increase in skin cells, T cells, and additional immune system cells
  • an accumulation of new skin cells on the surface of the skin
  • the development of the thick, scaly plaques associated with psoriasis

Typically, these effects first occur in response to a triggering event.

The symptoms of psoriasis often develop or become worse due to certain triggers. These can be environmentally or physically related. The triggers vary from person to person, but common psoriasis triggers include:

What triggers a psoriasis flare-up?

These same triggers can also prompt a flare-up of psoriasis in some people. However, not all common triggers have the same effect on all people with psoriasis, and people can also have uncommon triggers.

You can identify your specific triggers by tracking when you develop psoriasis symptoms. For example, did you notice a flare-up after a stressful week at work? Did your symptoms become worse after drinking alcohol with friends? Noting when symptoms occur can help you determine potential psoriasis triggers and avoid them.

A doctor can also evaluate your medications and overall health to help you pinpoint possible triggers.

Tell your doctor about any prescription or over-the-counter medications you may be taking. If they suspect your medication is causing your outbreaks, they may switch you to another medication or change the dosage.

Do not stop taking any medications unless a doctor instructs you to do so. Doing so can sometimes result in worsening health conditions or serious side effects.

While you can’t change your genes, you can prevent psoriasis flare-ups by managing your symptoms with consistent treatment. These include:

Aside from medical treatments, making certain lifestyle changes can also reduce your risk of a psoriasis flare-up. Possible changes include:

Reducing stress

While stress can have a negative impact on anyone, it may trigger symptoms in people with psoriasis.

The body tends to have an inflammatory reaction to stress. This response can lead to the onset of psoriasis symptoms. You can try reducing the amount of stress in your life by:

Taking care of your skin

Some people’s skin injuries, such as sunburns and scrapes, trigger psoriasis. However, practicing good skin care for psoriasis can help prevent these types of injuries.

Take extra precautions when engaging in activities that may cause skin injury. This can include:

  • using sunscreen and wearing a hat when spending time outside to avoid sunburn
  • wearing protective gloves when handling harsh chemicals or washing dishes
  • exercising caution when engaging in outdoor activities and contact sports, such as basketball or football

Reducing your risk of infection

Viral, fungal, and bacterial infections put stress on the immune system, which can trigger psoriasis by causing an inflammatory reaction.

Strep throat, in particular, is associated with the onset of psoriasis symptoms, especially in children. However, psoriasis flare-ups may occur after an earache, tonsillitis, or a respiratory or skin infection. You can reduce the risk of these infections by:

  • washing your hands often throughout the day, especially before eating
  • avoiding sharing cups and utensils with other people
  • cleaning any wounds thoroughly and covering the wound to prevent infection
  • avoiding direct contact with people who are sick

You can also take steps to improve your immune health to help prevent psoriasis flare-ups.

Eating a nutritious diet

Eating a nutritious diet that focuses on lean protein, whole grains, fruits and vegetables, and healthy fats can support your overall health and may help reduce psoriasis symptoms.

If you are overweight or have obesity, losing weight by eating a nutritious long-term eating plan and exercising regularly may help prevent psoriasis flare-ups.

A nutritionist can help you figure out how much food and which foods you should eat every day to maintain a moderate weight.

Read more about foods that may support your overall health with psoriasis.

Though some genes are associated with the development of psoriasis, scientists do not completely understand why psoriasis develops in some people and not others with those genes. Psoriasis likely results from a combination of genetic and lifestyle factors.

Though there is no cure for psoriasis, you can prevent and manage the symptoms with the help of healthcare professionals.

Working with your doctor to find treatments that relieve the itching and discomfort can ease psoriasis symptoms.

Taking steps to identify triggers for your symptoms and limiting your exposure to these triggers can also help prevent future flare-ups.