Lupus (Systemic Lupus Erythematosus)

What happens in lupus

In lupus, the immune system makes antibodies against the body's own cells, including against material in cell nuclei. These autoantibodies form immune complexes that deposit in tissues and trigger inflammation. Lupus is not contagious and is not related to HIV or cancer. The term "lupus" on its own usually means systemic lupus erythematosus.

Types of lupus

• Systemic lupus erythematosus (SLE): the most common and serious form, affecting multiple organs. See also systemic lupus erythematosus.
• Cutaneous lupus: affects only the skin. Discoid lupus causes scarring, coin-shaped patches, often on the face and scalp.
• Drug-induced lupus: triggered by certain medicines, such as hydralazine, procainamide and some TNF inhibitors. It usually resolves after stopping the drug.
• Neonatal lupus: a rare condition in babies of mothers with certain antibodies (anti-Ro/SSA), which can cause a rash and, rarely, heart block.

Symptoms

Lupus looks different in each person, and symptoms often come and go.

Common

• extreme fatigue
• joint pain, stiffness and swelling, often in the hands, wrists and knees
• fever without infection
• butterfly (malar) rash across the cheeks and nose
• rashes on sun-exposed skin and sun sensitivity
• painless mouth or nose ulcers
• hair thinning or patchy hair loss
• fingers and toes turning white or blue in the cold (Raynaud's phenomenon)
• swollen lymph nodes
• dry eyes and mouth

Organ involvement

• Kidneys (lupus nephritis): often silent at first. Signs include swelling, foamy urine and high blood pressure. Affects up to about half of people with SLE.
• Heart and lungs: inflammation of the lining around the heart (pericarditis) or lungs (pleurisy), causing sharp chest pain worse on breathing.
• Blood: anemia, low white cells or low platelets.
• Brain and nerves: headaches, memory and thinking problems, mood changes, seizures and, rarely, stroke or psychosis.
• Blood clots: especially with antiphospholipid syndrome, which often accompanies lupus.

Causes and triggers

The cause is not fully understood. Lupus results from a combination of:

• genes: it runs in families, though most people with a family member with lupus do not develop it
• hormones: estrogen likely plays a role, explaining why women are affected far more often
• environmental triggers: ultraviolet light, infections (such as Epstein-Barr virus), smoking, some medicines, and stress

Flares can be triggered by sunlight, infections, stopping medicines, pregnancy, stress and lack of sleep.

Diagnosis

There is no single test for lupus. A rheumatologist combines symptoms, examination and tests:

• ANA (antinuclear antibody): positive in nearly everyone with SLE, but also in many healthy people, so a positive ANA alone does not mean lupus
• specific antibodies: anti-double-stranded DNA and anti-Smith antibodies are much more specific for lupus
• complement levels (C3, C4): often low during active disease
• blood count, kidney function and urinalysis to check for organ involvement
• antiphospholipid antibodies
• skin or kidney biopsy in some cases

Classification criteria from EULAR and the American College of Rheumatology require a positive ANA plus a weighted score of clinical and laboratory features.

Conditions that can look similar

Rheumatoid arthritis, Sjogren's syndrome, fibromyalgia, viral infections, rosacea and other autoimmune diseases can mimic parts of lupus.

Treatment

Treatment aims to control symptoms, prevent flares and protect organs, using the lowest effective doses.

• Hydroxychloroquine: recommended for almost everyone with SLE. It reduces flares, protects organs and improves survival. Yearly eye checks are needed because of a rare retinal side effect.
• NSAIDs: for joint pain and mild inflammation, with caution in kidney disease.
• Corticosteroids: such as prednisone, to control flares quickly, then tapered to the lowest dose possible because of long-term side effects.
• Immunosuppressants: methotrexate, azathioprine and mycophenolate for more active disease, and to reduce steroid use.
• Biologics: belimumab and anifrolumab for active SLE, and treatments such as voclosporin for lupus nephritis.
• Cyclophosphamide or rituximab for severe organ involvement.
• Anticoagulants if antiphospholipid syndrome is present.

Self-care

• sun protection: broad-spectrum sunscreen, hats and protective clothing every day
• regular exercise and pacing to manage fatigue
• no smoking
• vaccinations recommended for people on immunosuppressants
• heart health: control blood pressure and cholesterol, as lupus raises cardiovascular risk
• bone health: calcium, vitamin D and bone density checks when taking steroids

Lupus and pregnancy

Most women with lupus can have successful pregnancies, but they are higher risk. Planning pregnancy when lupus has been quiet for at least 6 months, continuing hydroxychloroquine, and close monitoring by a rheumatologist and maternal-fetal medicine specialist improve outcomes. Some medicines, such as mycophenolate and methotrexate, must be stopped before conception.

Outlook

Lupus has no cure, but outlook has improved greatly. With modern treatment, most people with lupus live a normal or near-normal lifespan. Kidney involvement, heart disease and infections are the main threats, so regular monitoring is essential.

Frequently asked questions

What are the early signs of lupus?

Early signs often include unexplained fatigue, joint pain and swelling, fever, a rash across the cheeks and nose or on sun-exposed skin, mouth sores, hair loss and fingers changing color in the cold. Symptoms can come and go, which makes lupus hard to recognize at first.

Is lupus life-threatening?

It can be, particularly when it affects the kidneys, heart, lungs or brain, or when infections occur. However, with early diagnosis and modern treatment, most people with lupus live a normal or near-normal lifespan.

Does a positive ANA test mean I have lupus?

No. A positive ANA is found in many healthy people and in other conditions. Nearly everyone with lupus has a positive ANA, but diagnosis requires typical symptoms and more specific tests, such as anti-dsDNA or anti-Smith antibodies.

What triggers a lupus flare?

Common triggers include sun exposure, infections, stopping medicines, stress, lack of sleep, pregnancy and certain drugs. Sun protection, taking medicines consistently and good self-care reduce flares.

Can lupus be cured?

There is no cure yet, but lupus can usually be controlled. Many people have long periods of low disease activity or remission with hydroxychloroquine and other treatments. New biologic medicines have expanded the options.