Worried about catching a cold or influenza (the flu)? Depending on your type of treatment for psoriatic arthritis (PsA), you may be more prone to infections. Common immunosuppressant drugs that are used to treat autoimmune diseases may make your immune system less active — and less able to fight bacteria and viruses.

This article will discuss how having psoriatic arthritis and using certain treatment options may affect your risk of common infections, including influenza.

Influenza Symptoms and Complications

Influenza is a contagious viral infection that can cause mild to severe illness. In a 2018 study by the Centers for Disease Control and Prevention (CDC), researchers found that about 8 percent of Americans get sick with influenza each flu season.

Symptoms of the flu include:

• Fever
• Upper respiratory symptoms (such as a cough, sore throat, and runny nose)
• Body aches (bone or muscle pain)
• Tiredness
• Headaches

Sometimes it can be hard to tell the difference between the flu and other types of viral and bacterial infections. Flu symptoms typically develop two days after getting infected with the virus. People are most contagious in the first three or four days of illness. Young children and immunocompromised individuals could be infectious for longer.

Most people are able to fight off the flu, but for some, infection poses the risk of complications. According to the Arthritis Foundation, people with rheumatic diseases like psoriatic arthritis are at a higher risk of flu complications.

Influenza complications include:

• Pneumonia
• Bronchitis
• Ear and sinus infections
• Worsening of preexisting chronic conditions, like congestive heart failure and diabetes

Psoriatic Arthritis and Risk of Infections

People with autoimmune diseases like psoriatic arthritis are at a higher risk of getting the flu and other infections. One reason: For people with different types of inflammatory arthritis like PsA, changes in the immune system may affect their ability to fight infections.

However, a bigger part of the increased risk comes from medications used to treat PsA. According to the Arthritis Foundation, immunosuppressant drugs for treating psoriatic arthritis are a major factor in the increased risk of infections.

Corticosteroids

People with psoriatic arthritis may be prescribed corticosteroids to help control joint pain, swelling, and stiffness. In a 2016 study, researchers found that people taking corticosteroids had a two to six times higher risk of some bacterial, viral, and fungal infections than people who weren’t taking these drugs. The researchers noted that the risk depended on the drug dose and a participant’s age and other medical conditions, such as diabetes.

Disease-Modifying Antirheumatic Drugs

Conventional disease-modifying antirheumatic drugs (DMARDs), such as methotrexate and leflunomide, are common PsA treatments. DMARDs help reduce inflammation and slow the progression of disease. Although these medications decrease immune system activity, a 2019 study found that among people with inflammatory rheumatic conditions — including psoriatic arthritis — who took methotrexate, only those with rheumatoid arthritis had an increased risk of infections.

However, the risk of infections linked with DMARDs rises if you’re taking a biologic, according to the Arthritis Foundation. Biologics are a type of DMARD that target specific parts of the immune system. Examples of biologics used to treat PsA include:

• Tumor necrosis factor (TNF) inhibitors
• Interleukin (IL)-1 and IL-6 inhibitors
• T-cell and B-cell inhibitors
• Janus kinase (JAK) inhibitors

Biologic medications affect how well the immune system fights off infections. If you’re taking this type of drug for psoriatic arthritis, it’s important to know that you’re at an increased risk of infections. That might sound scary, but forgoing treatment increases your risk of joint damage and uncontrolled arthritis. Your health care provider will fully assess your health before having you start a biologic treatment.

Strategies To Help Prevent Infections

Maintaining a healthy lifestyle is a good preventive strategy for warding off infection, whether or not you have psoriatic arthritis. Healthy lifestyle suggestions include:

• Be physically active.
• Wash your hands frequently.
• Eat healthy, whole foods.
• Try to get plenty of sleep.
• Avoid being around sick people for prolonged periods.
• Get recommended vaccines.

Psoriatic Arthritis and the Flu Vaccine

If you have psoriatic arthritis, you may wonder about the flu vaccine’s effect on your immune system. However, doctors encourage people, especially those with rheumatic disease, to get vaccinated for influenza.

Since psoriatic arthritis medications weaken the immune system, it’s even more important to protect yourself from getting sick. The CDC recommends that everyone receive the influenza vaccine each October, before flu season.

What Type of Flu Vaccine Should You Get?

If you have psoriatic arthritis and receive treatment that affects your immune system, doctors recommend getting a flu shot — the injected form of the flu vaccine. Injected vaccines contain an inactive form of the virus, whereas nasal sprays carry a live virus. The live-virus nasal spray vaccines could be dangerous for people with compromised immune systems.

What Other Vaccines Should You Consider?

Psoriatic arthritis and treatments for the disease suppress your immune system and make you susceptible to other bacterial and viral infections — not just the flu. It’s a good idea to get vaccinated for other types of infections as well.

Pneumonia is a bacterial infection of the lungs that can be dangerous for people with a compromised immune system. Doctors usually recommend getting the pneumonia vaccine every five years. Your doctor may also recommend getting the meningococcal vaccine, which protects against bacteria that can cause meningitis (inflammation of the brain and spinal cord), and the recombinant zoster vaccine to help prevent shingles.

If you have psoriatic arthritis, ask your health care provider which vaccines you should get, including the COVID-19 vaccine. They’ll consider your health status, the medications you take, and other important factors when making recommendations for you.

Talk With Others Who Understand

MyPsoriasisTeam is the social network for people with psoriasis and psoriatic arthritis and their loved ones. On MyPsoriasisTeam, more than 126,000 members come together to ask questions, give advice, and share their stories with others who understand life with psoriasis and psoriatic arthritis.

Do you have psoriatic arthritis and worry about your risk of infections? What measures do you take to avoid getting sick? Share your experience in the comments below, or start a conversation by posting on your Activities page.