While research shows that some people with psoriasis harbor certain gene mutations, this is not true for everyone with the disease. Psoriasis can affect people without a family history of the condition, but having a family member with the condition increases your risk.

There is a complex interplay of environmental and genetic factors that make a person susceptible to developing psoriasis. Onset triggers include infections like strep throat and HIV, stress, obesity, smoking, medications, or a severe sunburn or skin trauma.

In this article, learn more about how psoriasis can be inherited, treated, and what triggers it.

Overview

Psoriasis is a lifelong condition with no cure. According to the Psoriasis Foundation, it affects eight million people in the United States. Psoriasis tends to occur in cycles where it can flare up for weeks or months, or it can subside into periods of remission where symptoms are gone or significantly reduced. 

Psoriasis is an autoimmune disease which results from the body attacking itself. With psoriasis, white blood cells known as T helper lymphocytes (T-cells) mistakenly attack skin cells. Normally, white blood cells respond to an attack on the immune system by destroying invading bacteria and fighting infections.

The mistaken attacks from the immune system will cause skin cell production to go into overdrive. The excess skin cell production will cause new skin cells to develop too quickly. They are pushed to the skin’s surface and pile up.

The skin cell pileup results in the plaques that psoriasis is known for. The skin cell attacks also cause the skin to become red and inflamed.

Researchers don’t know why the immune system malfunctions in psoriasis, but they do know how to calm it down. Various treatments can help you manage symptoms of psoriasis. Incorporating healthy lifestyle habits and coping strategies can also help you manage symptoms and cope with the effects of psoriasis.

Psoriasis and Your Genes

Psoriasis is often diagnosed in people ages 15 to 35, but it can affect anyone regardless of age, including children. According to the National Psoriasis Foundation, about one-third of the people who get psoriasis are under age 20, and around 20,000 new diagnoses every year are children under the age of 10.

Genetics becomes important when one parent has psoriasis. According to the National Psoriasis Foundation, having a parent with the condition gives you a 28% chance of having psoriasis. If both of your parents have the condition, your risk jumps to 65%.

Researchers believe that mutated genes, in combination with environmental triggers, must interact to cause a person to develop psoriasis.

While rare, it is possible to get psoriasis without a family history, but the chance applies to a small group. In this case, a person has spontaneous gene mutations that can lead to psoriasis when triggered by environmental factors.

What Research Says

When understanding genetic causes of psoriasis, researchers look to the immune system. Numerous studies have found that skin cells affected by psoriasis contain large amounts of cytokines—cell proteins that create inflammatory processes.

Risk Factors Plus Gene Mutations

Without risk factors and gene mutations, it is unlikely that a person will develop psoriasis.

Skin cells in psoriasis also contain gene mutations. Specific variations of genes are called alleles.

Studies going back to the 1980s found that specific alleles might be responsible for inherited psoriasis. Later studies found HLA-Cw6, which researchers now believe is linked to the development of psoriasis. Newer research strives to understand the connection between HLA-Cw6 and psoriasis better.

Around 25 different regions in the human genome (human genetic makeup) might be connected to psoriasis. Genetic studies give researchers some idea of the risk connected to psoriasis.

Among the gene mutations, researchers understand how some may behave and how they might lead to psoriasis. Commonly studied and recognized gene mutations associated with psoriasis include CARD14 and IL23R:

  • CARD14: This gene mutation was first identified in 2012. Changes to CARD14 can lead to high levels of inflammation. Studies have also found that CARD14 can lead to psoriasis on its own and when other triggers are present.
  • IL23R: This gene plays a role in the way the immune system increases the inflammatory response.

Environmental Triggers

An environmental trigger is a factor in a person’s environment that plays a part in bringing about the development of a disease. There are environmental risk factors associated with the development of psoriasis and the disease’s progression.

Genetics Unclear

While genetic studies are helpful, they only give us a small picture of a person’s risk for developing psoriasis. There is still a lot to learn about what causes and triggers psoriasis and how it is passed down from parent to child.

Environmental risk factors associated with the development of psoriasis include hormones, infection, stress, skin trauma, obesity, smoking, and heavy alcohol consumption. These environmental factors are also associated with flare-ups (periods of high disease activity).

Hormone Changes

The incidence of psoriasis is about the same regardless of sex. But researchers have found that sex hormones can have a significant effect on how the condition develops in females:

  • Puberty: Hormonal changes at female puberty can trigger or worsen psoriasis. During female puberty, the body starts making the sex hormones estrogen and progesterone. The rush of these hormones can cause or worsen psoriasis.
  • Menopause: Reduced estrogen during menopause can be a major factor in the occurrence or the worsening of psoriasis symptoms in people who already have the condition.
  • Pregnancy: Some people will get psoriasis for the first time after having a baby. Studies have found that the reason this might occur postpartum is because of dropping estrogen and progesterone levels.

Pregnant people who already have psoriasis might develop psoriatic arthritis (PsA) after their baby is born. PsA is a type of inflammatory arthritis that affects some people with psoriasis.

PsA occurs in 10% to 30% of people with psoriasis, and pregnancy may act as a triggering event for the condition. Between 30% to 40% of people can relate the onset of their PsA to their postpartum period.

If someone has a C-section (surgical delivery of a baby), they may experience what doctors call Koebner’s phenomenon. This is a flare-up of psoriasis symptoms near a skin injury on the body.

Infection

The connection between psoriasis and infection is well established in the research. People with HIV are more likely to develop psoriasis.

Strep throat has been linked to guttate psoriasis, a type of psoriasis that causes small, red, scaly rashes to develop. People who get frequent strep infections are at an increased risk for psoriasis.

Some viruses—including papillomaviruses and retroviruses—have also been linked to psoriasis.

Stress 

Researchers think the way the immune system responds to emotional and mental pressures is similar to how it responds to physical health problems, including skin injuries and infections. The body responds to stressors with an inflammatory response that eventually becomes chronic.

Stress and psoriasis seem to go together. Stress can make psoriasis worse, and psoriasis symptoms can cause you to feel stress. Fortunately, there are ways to reduce and manage stressors—both life stressors and those associated with managing the aspects of the disease.

Skin Trauma

Psoriasis can develop in areas where the skin has been injured. This is the result of Koebner’s phenomenon where any type of skin injury—a bad scratch, a sunburn, a bug bite, a tattoo, or a vaccination­—can trigger psoriasis.

Weight

Being overweight and a condition called metabolic syndrome can increase your risk for developing psoriasis. The risk for metabolic syndrome is closely connected to obesity and lack of physical activity. It is common in people with psoriasis, and obesity is strongly connected to the onset and exacerbation of psoriasis.

The presence of metabolic syndrome in people with psoriasis ranges from 20% to 50%, with the risk of having the condition being at least double compared to people without psoriasis.

Some Medications

In some people, psoriasis can be drug induced, where the discontinuation of the drug can clear psoriasis. This is common in people who had no previous history of the condition.

Metabolic Syndrome

Metabolic syndrome refers to a cluster of conditions that increase a person’s risk for heart disease, stroke, and diabetes. Conditions that are part of metabolic syndrome are high blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol levels.

Psoriasis can also continue to develop even after the drug causing it has been discontinued. This is common in people who have a family history of the condition.

Some medications linked to drug-induced psoriasis include beta blockers, lithium, anti-malarial drugs, nonsteroidal anti-inflammatory drugs, antibiotics, ACE inhibitors, and TNF inhibitors.

Smoking and Alcohol

Smoking and alcohol have both been linked to the development of psoriasis. Current smokers and former smokers are both at risk, but quitting smoking does bring down that risk. Heavy alcohol drinkers also have a higher risk for psoriasis onset and more severe disease.

Weather

Weather usually doesn’t lead to the onset of psoriasis. But weather and seasonal changes can make your psoriasis worse.

According to a study reported in 2015 in the Journal of the American Academy of Dermatology, most people with psoriasis will have clearer skin in the summer months and moderate to severe symptoms in the winter months.

Seasonal changes can also affect the way treatments work. For example, the researchers found that biologic drug therapies for psoriasis seem to be more effective in the warmer weather months.

Treatment 

The goal of psoriasis treatment is to stop skin cells from growing too quickly, slow down inflammation, and reduce the potential for skin damage. The right treatment plan will clear your skin and improve your quality of life.

Of course, not every treatment will work for you, so your doctor will help you find therapies that might be effective for you. Your doctor will start with the mildest approach and move to more aggressive therapies if mild ones fail.

Treatments for psoriasis include topical medicines, phototherapy, systemic drugs, and biologics.

Topical Treatments

Topical treatments are applied directly to the skin and are usually a first-line therapy for mild to moderate psoriasis. Topical treatments can either be over-the-counter (OTC) or prescribed by your doctor.

OTC topicals include salicylic acid, coal tar, and products that contain aloe vera, jojoba, zinc pyrithione, or capsaicin. Prescription topicals for treating psoriasis include nonsteroidal creams to control excessive skin cell production and topical corticosteroids to reduce skin inflammation.

Phototherapy

Also considered a first-line treatment for psoriasis therapy, phototherapy focuses specific types of light onto the skin. Both ultraviolet B (UVB) and psoralen and ultraviolet A (PUVA) are commonly used to treat moderate to severe psoriasis.

Light therapy treatments can be done at your doctor’s office, a therapy clinic, or at home using a phototherapy unit. People who use light therapy for psoriasis should pay attention to skin changes after treatment. Minor side effects, including redness and itching, temporarily aggravate psoriasis skin symptoms.

Systemic Drugs

Systemic treatments for psoriasis include medicines that work to affect the entire body. These medicines are usually prescribed to people who haven’t gotten relief from topical medicines or light therapy. Systemic medicines are either taken orally or given by injection.

Common systemic medicines prescribed for treating psoriasis include:

  • AcitretinMethotrexateCyclosporineSulfasalazine

Biologic Drugs

Biologic drugs to treat psoriasis work by blocking the action of specific cells and proteins in the immune system connected to psoriasis. These drugs are administrated with an injection or IV infusion. Several biologics have been approved by the Food and Drug Administration for treating moderate to severe psoriasis.

Studies have demonstrated that these drugs are quite effective for treating psoriasis. But they need to be used continuously, because stopping and starting a biologic can cause reduced effectiveness and severe side effects. With consistent use, a biologic can remain an effective and safe option for many years.

Biologics used to treat severe to moderate psoriasis include:

  • Cimzia (certolizumab pegol)Cosentyx (secukinumab)Enbrel (etanercept)Humira (adalimumab)Remicade (infliximab)Simponi (golimumab)Skyrizi (risankizumab)Stelara (ustekinumab)Taltz (ixekizumab)

Lifestyle Therapies

Lifestyle therapies can sometimes improve symptoms of psoriasis. This includes diet changes, exercise, stress management, exposure to sunlight, daily baths, and the use of skin moisturizers.

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Diet: For some people, diet triggers might increase inflammation and worsen skin symptoms. While there is no specific diet for psoriasis, some people with the condition find that by cutting out foods and drinks that aggravate symptoms, they experience less inflammation and clear skin.

A survey of 1,200 people with psoriasis published in 2017 in Dermatology and Therapy found that over half of the respondents said they noticed symptom improvement after they reduced their intake of alcohol, gluten (a protein found in wheat, barley, and rye), and nightshade foods (white potatoes, tomatoes, eggplant, etc.).

Participants also had improvements when they added fish oil/omega-3, vegetables, and oral vitamin D to their diets.

People on specific diets—including a Pagano diet that emphasized fruits and vegetables, vegan diets, and paleo diets containing mainly whole foods—also reported improved symptoms.

Stay active: Staying active is important to staying healthy with psoriasis. Research shows that having psoriasis puts you at risk for a whole host of comorbid conditions, including cardiovascular disease, metabolic syndrome, obesity, and depression.

Exercise can help stave off unwanted health problems. You should talk to your doctor before you start an exercise program so that they can help you find a program that works for your unique health situation.

Practice stress management: There is a clear link between stress and psoriasis. You are more likely to have flares when you are stressed. Relaxation therapies such as deep breathing, massage, and yoga may help you reduce stress.

Relaxation therapies need to be practiced regularly to be effective. If you find you are struggling to cope with the effects of psoriasis, consider seeing a therapist who works with people who have psoriasis and other chronic diseases.

Sunlight exposure: Exposure to small amounts of sunlight can help reduce some skin symptoms. However, too much sun leads to psoriasis outbreaks and increases the risk for skin cancer. Ask your dermatologist how much sunlight exposure is safe for you.

Daily baths: Soaking in a mineral bath can help hydrate and soften your skin. Adding Dead Sea salts, Epsom salts, and colloidal oatmeal can help to lessen skin inflammation. Make sure you stay away from hot water and harsh soaps, which can aggravate skin symptoms.

Moisturize: Apply moisturizer to help to soothe dry, inflamed skin. A good moisturizer can also combat symptoms of itching and flaking.

Frequently Asked Questions

What is the main cause of psoriasis?

Psoriasis is caused by your overactive immune system mistakenly attacking itself. An overactive immune system sends faulty messages and misidentifies healthy tissues for harmful ones. This response leads to too much inflammation.

With psoriasis, that inflammatory response causes skin cell production to go into overdrive, causing new skin cells to build up at the skin’s surface.

How is psoriasis diagnosed?

To diagnose psoriasis, your doctor examines your skin, nails, and scalp for signs of the condition. They will also want to know about other symptoms you might have including itchy skin, joint pain, swelling, and stiffness, especially in the morning.

Your doctor will also want to know if you have blood relatives who have psoriasis, psoriatic arthritis, or other autoimmune diseases. You might also be asked about risk factors for psoriasis, including increased stress or recent traumatic skin injury.

Sometimes, a doctor or a dermatologist will do a skin biopsy. This involves taking a skin sample and looking at it under a microscope. A skin biopsy can help determine the type of psoriasis a person has and rule out other conditions.

How does psoriasis start?

Psoriasis will initially start as small, red bumps, which grow and form scales. The skin in the affected area will appear thick. It might bleed if you try to rub off the scales. Early skin symptoms generally appear on the elbows, knees, and scalp, but they can appear anywhere on the body.

Early psoriasis might also affect the nails, causing pits—small depressions in your fingernails or toenails. They might crack and come loose from the skin. These symptoms are often related to nail psoriasis.

If you suspect you might have psoriasis, see your doctor. If you have been diagnosed with psoriasis, let your doctor know if skin symptoms become severe or widespread, if skin is extremely painful, or if symptoms don’t improve with treatment.

Also, let your doctor know if you experience joint problems, such as painful swelling, or find it harder to perform daily tasks due to joint symptoms.

Summary

Psoriasis runs in families, and genes play a role in the condition. However, having a family member with the condition doesn’t mean you will eventually develop psoriasis. Environmental triggers—including hormonal changes, infections, skin trauma, and more—interact with genes to lead to the condition.

A Word From Verywell

While researchers can’t predict who will eventually develop psoriasis, certain risk factors are preventable. Getting those under control can reduce your risk. Managing your weight, reducing stress levels and alcohol intake, and avoiding or quitting smoking are all ways to reduce your risk.

Even if you do go on to develop psoriasis, the condition is treatable, with plenty of treatment options available to soothe skin and inflammation, stop overactive skin reproduction, and remove excess dead skin.

Don’t forget to prioritize your mental and emotional health. Psoriasis not only affects your body, it also affects your emotions and self-image. Ask your doctor about helpful resources, including support groups and mental health counseling options.