Lupus and infections

Systemic lupus erythematosus (SLE), otherwise known as lupus, is a chronic condition that results from a malfunctioning immune system. People with lupus are more likely to experience infections and infection-related complications, because their immune system is weakened by both the disease and the medicines used to treat it.

The most common infections in people with lupus affect the respiratory tract, the skin and the urinary system.

Lupus and the immune system#

Your immune system is made up of many types of immune cells and proteins that protect your body against disease and infection. When your body detects germs, such as bacteria or a virus, the immune system responds and defends you against these invaders. Once the threat is dealt with, it switches off and everything returns to normal.

In conditions like lupus, the immune system malfunctions and attacks the healthy tissues it is meant to protect, including the skin, joints, kidneys and the lining of the heart and lungs. Instead of switching off, the attack continues. This causes ongoing inflammation, pain and tissue damage.

Many people with lupus take immunosuppressive medicines to control the immune system and help prevent this inflammation and pain. Unfortunately, these medicines affect the whole immune system, not just the malfunctioning cells. In particular, they can reduce the activity of white blood cells, which weakens the body’s response to bacterial infection.

Lupus and common infections#

People with lupus catch the same kinds of infections as everyone else. They are also at risk from “opportunistic” organisms, such as fungi, which are more likely to cause infection when the immune system is weakened. Although people with lupus are more susceptible to these microorganisms, the resulting infections are usually mild.

Some of the more common infections include:

• herpes zoster (virus)
• Staphylococcus aureus (bacterium)
• Escherichia coli (bacterium)
• Salmonella (bacterium)
• Candida albicans (fungus)

Diagnosing an infection in someone with lupus#

It can be difficult to diagnose an infection in someone with lupus, because the symptoms may closely mimic those of lupus itself. For instance, it can be hard to tell whether joint pains and fever are caused by a lupus flare or an infection. To complicate matters further, an infection can trigger a lupus flare.

A chronic low-grade fever may be normal for someone with lupus, so it helps to take your temperature at the same time each day. See your doctor if you have a temperature that is higher than usual, or any symptoms that are not typical for you.

Methods used to diagnose an infection may include:

• a physical examination by your doctor
• blood tests
• urine tests
• cultures of the throat
• a chest x-ray

Treating an infection in someone with lupus#

Treatment depends on the type of infectious agent:

• Bacterial infections are treated with antibiotics. More serious infections may need intravenous antibiotics and hospital admission, particularly if you are taking immunosuppressive medicines for lupus.
• Fungal infections are treated with antifungal medicines, which may come as creams, suppositories or tablets.
• Viral infections such as sinus infections, bronchitis and colds often do not respond to treatment and should not be treated with antibiotics. (Overusing antibiotics makes bacteria more resistant and harder to treat.) Your doctor may suggest over-the-counter remedies to ease symptoms while the infection runs its course, such as pain relievers for pain or short-term nasal sprays for a blocked or runny nose. Antiviral medicine may be used for some viral infections, such as herpes zoster.

Some people with lupus have an allergic reaction to sulfa antibiotics, which can cause increased photosensitivity, skin rashes and lower white blood cell counts. This type of antibiotic should be avoided wherever possible.

Reducing the risk of infection if you have lupus#

Because infections can be harder to treat when you have lupus, the best thing you can do is lower your risk in the first place. You can do this by:

• washing your hands thoroughly
• treating any cuts and grazes promptly
• keeping up high standards of personal hygiene
• cleaning your home regularly and thoroughly
• avoiding items that commonly harbour germs, such as old, soiled kitchen sponges
• avoiding contact with anyone who has an infection
• eating a well-balanced, nutritious diet
• taking your temperature daily so you know what is normal for you
• talking to your doctor about annual influenza (flu) and pneumococcal immunisations
• consulting your doctor before any dental or surgical procedure, as they may recommend a preventive course of antibiotics

Key points#

• People with lupus are more prone to infection because their immune system is weakened by both the disease and the medicines used to treat it.
• The most common infections affect the respiratory tract, skin and urinary system.
• A malfunctioning immune system causes ongoing inflammation, pain and tissue damage.
• Common infections include fungal ones such as Candida albicans.
• It can be hard to tell whether symptoms like joint pain and fever are caused by a lupus flare or an infection.

Where to get help#