The Relationship Between Psoriasis and Skin Infections

Having psoriasis, an autoimmune condition that causes inflamed skin patches, can make you more likely to develop certain skin infections.

A combination of factors—such as a damaged skin barrier, an abnormal immune system, and psoriasis medications—can allow harmful bacteria, viruses, and fungi to enter the body, leading to a skin infection.

It’s important to treat skin infections to avoid complications. Because psoriasis and skin infections can trigger similar symptoms, it can sometimes be hard to tell when a skin infection has developed. Knowing all the signs can help you get any treatment you might need as soon as possible.

While anyone can develop a skin infection, the chances may be greater if you have an immune system disease like psoriasis. There are several potential reasons behind this.

Skin Barrier Damage

One of the skin’s primary duties is to keep out harmful microorganisms like bacteria, viruses, and fungi. Psoriasis weakens the skin’s protective barrier, making it easier for infectious germs to invade the body.

Scratching your skin may further damage the skin barrier. A main symptom of psoriasis is itchiness, and while it might initially feel satisfying, scratching psoriasis plaques can damage the skin barrier. This creates open wounds that allow bacteria to enter the body and an infection to develop.

Immune System Dysfunction

As an autoimmune condition, psoriasis causes the body’s immune system to overreact and mistakenly attack healthy skin cells. This reaction leads to the inflammation and skin plaques that are trademark symptoms of psoriasis. Your immune system helps fight off infections, and this abnormal immune response may affect defense against infections.

Medications

Biologic drugs, a type of medication used to treat psoriasis, can target an overactive immune system. However, their use can also increase the risk of certain serious infections.

People with psoriasis who took biologics were more likely to develop a serious skin infection, a yeast infection on the skin, and even pulmonary (lung) or gastrointestinal infections.

Presence of Other Health Conditions

People with psoriasis are more likely to have other conditions such as diabetes, being overweight, and obesity. These conditions can cause an abnormal immune system response.

This higher rate of immune system-affecting health conditions may explain why people with psoriasis are more likely to develop severe skin and skin structure (skin and surrounding soft tissue) infections.

A skin infection can develop when bacteria, viruses, fungi, or parasites invade the body. The symptoms vary based on the exact type of infection, but common symptoms include:

• Swelling
• Itchiness
• Redness or discoloration
• Pain
• Pus
• Rashes
• Skin that’s warm to the touch

The appearance of a skin infection can often mimic a psoriasis outbreak. For example, pustular psoriasis may look like a skin infection; both can cause pus-filled, itchy bumps that form on inflamed skin. However, a skin infection may have additional signs, like a fever and pain.

Several skin infections may be likelier for people with psoriasis. Some of the most common include:

• Staph infections: Psoriasis can increase your risk of developing a staph infection. While the staph infection-causing bacteria Staphylococcus aureus are commonly found on the human body, research has suggested that people with psoriasis are 4-5 times likelier to have the bacteria on their skin than those without psoriasis. An overabundance of this bacteria can lead to an infection.
• Methicillin-resistant Staphylococcus aureus (MRSA): MRSA is a type of staph infection that doesn’t respond to many antibiotics. People with psoriasis who have been hospitalized are at a higher risk for developing an MRSA skin infection.
• Fungal infections: People with psoriasis are more likely to develop a Candida fungus infection, which can cause thrush, vaginal yeast infections, diaper rash, and other more serious infections. An overgrowth of Candida yeast causes the infection, and the fungus seems to be present in greater quantities on the skin of people with psoriasis.
• Impetigo: This contagious bacterial skin infection is more likely to develop in people with certain skin conditions, including psoriasis. In these cases, the damaged skin barrier from psoriasis can make it easier for Staphylococcus or Streptococcus bacteria to enter the body, triggering an impetigo infection.

You can reduce the chances of skin infections by managing your psoriasis and minimizing or avoiding exposure to the germs that can infect you. Here’s what experts recommend:

• Avoid the possibility of skin injury: Injuries include a cut, bug bite, or sunburn.
• Limit your exposure to psoriasis triggers: Triggers include stress, cold and dry weather, certain medications, and tobacco and alcohol use.
• Avoid scratching your psoriasis spots: You can try to do this by following your treatment plan, using cold compresses, and moisturizing daily.
• Keep your hands clean: Thoroughly wash your hands throughout the day, especially before and after eating.
• Keep cuts or wounds clean: You should also cover them with gauze or a bandage to allow the area to heal.
• Avoid sharing personal items: Don’t share towels, cosmetics, or clothing. If any items have made contact with a skin infection, wash them.
• Wear loose-fitting clothing. Choose lightweight, breathable fabrics to prevent moisture from building up on your skin, particularly in areas that may rub on psoriasis patches.
• Talk to your healthcare provider: Discuss your psoriasis and any other health conditions, such as diabetes, that may increase your risk of developing skin infections.

Skin infections are believed to be the third most common medical concern treated in urgent care settings, emergency rooms, and healthcare offices.

Consider seeing a healthcare provider if you think you have any signs of a skin infection, if you have psoriasis and suspect a skin infection, or if you’re unsure whether your symptoms are due to psoriasis or an infection.

Untreated skin infections can lead to more serious complications, such as gangrene, sepsis, or necrotizing fasciitis (flesh-eating disease). Getting your symptoms evaluated in a timely manner can avoid complications. A healthcare provider can diagnose and treat any infection you may have.

Diagnosing a psoriasis-related skin infection might involve a visual examination, a skin biopsy (taking and testing a small sample of skin), swab tests, and blood tests. Treatment will depend on the exact infection. It may involve oral or topical antibiotics, antiviral medications, or antifungal medications. In some cases, it may be necessary to undergo a procedure to drain pus.

Having psoriasis can increase the risk of developing certain skin infections, like MRSA and candidiasis. This is likely due to the damaged skin barrier and immune system dysfunction accompanying psoriasis, though other factors may also be at play.

See a healthcare provider if you notice signs of skin infection, such as pain, fever, swelling, and pus. You can also help prevent skin infections by keeping your hands clean, wearing loose-fitting clothing, avoiding contact with potentially infected items, and managing your psoriasis.