Why Do People With Lupus Get Infections So Easily?

An individual with lupus is more susceptible to infection than most people for two reasons:

1. Lupus directly affects a person's immune system and reduces his or her ability to prevent and fight infection.
2. Many of the drugs used to treat lupus suppress the function of the immune system and leave the body more prone to infection.

Effects Of Medications Used In The Treatment Of Lupus

Cortisone-like drugs (prednisone) and cytotoxic drugs such as azathioprine (Imuran) and cyclophosphamide (Cytoxan) increase a person's susceptibility to infections because they suppress both normal and abnormal immune system function.

However, controlling lupus is usually more important than the danger posed by a possible infection due to the use of immunosuppressive medications.

The risk of infection parallels the dose and the duration of treatment with steroids:

• a daily dose of 20 mg. of prednisone is enough to impose a significant risk of infection
• taking steroids every other day ("alternate day" treatment) decreases the risk and incidence of infections

Direct Effects of Lupus On The Immune System

People with lupus have abnormalities in their immune systems, so they are more likely to develop infections. They are more susceptible to infection even if they do not take corticosteroids. Lupus experts such as Dr. Marian Ropes sparingly used steroids in treating her patients in the 1940s and 1950s. Yet, the data she published showed that the majority of her patients developed serious infections, even on low-dose steroids.

Types Of Infection In SLE

Infections in people with lupus fall into two categories.

1. The first category includes infections with organisms that can affect persons with lupus and the general population:
   • streptococcus (which causes strep throat)
   • staphylococcus (which causes staph infections).
2. The second category consists of "opportunistic" infections, which are caused by organisms that bring about disease only when the immune system is weakened. Most opportunistic infections are one of three kinds:
   • fungal
   • parasitic
   • protozoan.

Fortunately, only a few individuals will need aggressive hospital treatment for infections. The most common infections in people with lupus usually do not require hospitalization. These common infections usually involve:

• the respiratory tract
• the urinary tract.

However, infections in people with lupus tend to last longer and require a longer course of treatment with antibiotics than infections in people who do not have lupus.

In addition, people with lupus are at an unusually high risk for contracting:

• salmonella (a bacteria)
• herpes zoster (a virus)
• candida (yeast)

Fevers In Lupus

Anyone with lupus who experiences a fever should be thoroughly evaluated, especially if they are also taking aspirin, non-steroidal medications (e.g., Advil, Naprosyn), or steroids, which lower body temperature. Fevers in lupus may be due to:

• an infection
• a drug reaction
• active lupus.

Clinical Evaluation Of Possible Infection

Active lupus and infection may share many symptoms. Furthermore, infection can bring on a lupus flare, or can be difficult to distinguish from a lupus flare. For example, fever and decreased energy are nonspecific symptoms that may be associated with either a lupus flares or an infection.

More specific symptoms, like sore throat or pain on taking a deep breath, may also occur with either a flare of lupus or with infection. Therefore, it is important for a person with lupus to contact his or her physician whenever symptoms are suggestive of either a disease flare or an infection.

Laboratory Tests Used

• White blood cell counts
  • this test can help a physician distinguish an infection from a lupus flare
  • a low white blood cell count usually suggests active lupus (although certain viruses can also give a low white count)
  • a high white blood cell count suggests infection
• Culture of throat, urine, blood or stool
• Complete blood count (CBC)
• Chest X-ray

Some physicians find a C-reactive protein (CRP) blood test to be helpful in deciding whether a person has active lupus or an infection, but this is still controversial.

Persons with suspected life-threatening infections of unknown source may need to be hospitalized so they can be observed and necessary cultures can be taken. Tests which are performed to help make a rapid diagnosis may include:

• gallium scanning
• bone marrow biopsy
• lymph node biopsy
• bronchoscopy

Treatment and Prevention of Infection

The treatment of infections in a person with lupus is basically the same as for anyone else; even people taking high doses of immunosuppressive medications for their lupus may respond well to antibiotics.

However, the use of sulfa antibiotics to treat infections in people with lupus should be avoided whenever possible. Thirty percent of people with lupus are allergic to sulfa antibiotics. In addition, these types of antibiotics can:

• increase photosensitivity
• increase skin rashes
• lower white blood cell counts.

Avoiding The Risks of Infection

Infection poses a risk to all people with lupus. However, those treated with immunosuppressives or steroids are at higher risk. To prevent possible infections, people at high risk for infection often benefit from taking antibiotics before dental treatment or surgical procedures. In general, individuals with lupus should avoid exposure to people with colds or other infections.

Preventing Infection With Immunizations

The risk of certain types of infection can be decreased with immunization (vaccinations). Nearly all individuals with lupus are vaccinated against a variety of diseases with little difficulty.

However, it is theoretically possible that immunization with vaccines that use live viruses will result in a lupus flare. Nevertheless, polio, measles, and tetanus vaccines, which all use live viruses, have been given to hundreds of thousands of people who have lupus, with no adverse reactions. Passive immunization (i.e., vaccinating with a killed virus), poses no problems. Gammaglobulin is an example of a vaccine which uses a nonspecific antibody instead of a live virus.

It should be noted that people with lupus may have adverse reactions to two types of immunizations.

1) First, some who receive allergy shots (immunotherapy) will experience a lupus flare following treatment.

• In 1989, the World Health Organization recommended that people with autoimmune diseases should not receive certain types of allergy shots.
• Allergy shots might cause the person to make more anti-DNA and other lupus-related antibodies in addition to making antibodies against the agent causing the allergy.
• People with lupus are advised to consult their rheumatologist before receiving any type of allergy immunotherapy.

2) Some lupus patients may also experience difficulties after receiving influenza, or "flu" vaccines.

• Flu vaccines may not work as well if the individual has lupus.
• Nevertheless, most rheumatologists do recommend vaccinations against the flu.

Related Information

On this website
Flu & Pneumonia Shots
Vaccinations

On the Internet
An Ounce of Prevention Keeps the Germs Away - Center for Disease Control (CDC)
MedlinePlus: Bacterial Infections
MedlinePlus: Fever
MedlinePlus: Fungal Infections
MedlinePlus: Infections Topics
Medplus: Viral Infections