Lupus is a chronic autoimmune disease in which the immune system, which normally protects the body from infection, mistakenly attacks the body's own tissues. It can affect almost any organ, including the skin, joints, kidneys, heart, lungs, blood and brain. Because its symptoms vary so much and often mimic other illnesses, lupus is sometimes called "the great imitator."
Who Gets Lupus?
Lupus can affect anyone, but about 9 out of 10 people with the condition are women. It most often begins between the ages of 15 and 45. It is more common, and often more severe, in people of African, Asian and Hispanic descent.
Types of Lupus
Systemic lupus erythematosus (SLE) is the most common and serious form. It can affect multiple organs, and when people say "lupus," they usually mean SLE.
Cutaneous lupus affects only the skin, causing rashes and sores, usually on sun-exposed areas. Discoid lupus, which causes round, scaly patches that can scar, is one type.
Drug-induced lupus is triggered by certain medicines, such as hydralazine, procainamide and isoniazid. Symptoms usually go away once the medicine is stopped.
Neonatal lupus is a rare condition in which a baby is affected by antibodies passed on from the mother. Most symptoms fade within months, but it can occasionally cause a serious heart rhythm problem called congenital heart block.
What Causes Lupus?
The exact cause is unknown. It likely results from a combination of genetic susceptibility and environmental triggers, which may include:
- sunlight (UV exposure)
- infections, such as Epstein-Barr virus
- certain medicines
- hormonal factors, which may explain why lupus is so much more common in women
- smoking
- Symptoms
Lupus symptoms often come and go. Periods when the disease is active are called flares, and quieter periods are called remission. Common symptoms include:
- extreme fatigue
- joint pain, stiffness and swelling
- a butterfly-shaped rash across the cheeks and bridge of the nose (malar rash)
- sensitivity to sunlight, with rashes that appear or worsen after sun exposure
- unexplained fevers
- mouth or nose ulcers
- hair loss
- fingers and toes that turn white or blue in the cold (Raynaud's phenomenon)
- chest pain when breathing deeply, caused by inflammation around the lungs or heart
- swelling in the legs or around the eyes, which can signal kidney involvement
- Serious Complications
Lupus can cause serious organ damage if not controlled.
Kidneys. Lupus nephritis, or inflammation of the kidneys, affects many people with SLE and can lead to kidney failure without treatment.
Heart and blood vessels. People with lupus have a higher risk of heart disease, blood clots and stroke.
Blood. Lupus can cause anaemia, low white blood cell counts and low platelets.
Brain and nervous system. Headaches, memory problems, seizures and mood changes can occur.
Pregnancy. Lupus raises the risk of miscarriage, pre-eclampsia and premature birth. Pregnancy should be planned when the disease has been stable for some time, with close medical supervision.
Diagnosis
No single test confirms lupus. Doctors combine symptoms, a physical examination and laboratory tests. Key tests include:
- antinuclear antibody (ANA) test, which is positive in almost all people with SLE but also in many people who do not have lupus, so a positive result alone is not a diagnosis
- specific antibody tests, such as anti-double-stranded DNA (anti-dsDNA) and anti-Smith antibodies, which are more specific to lupus
- complement levels (C3 and C4), which often fall during active disease
- blood counts, kidney function tests and urine tests to check for organ involvement
A rheumatologist usually confirms the diagnosis and oversees treatment.
Treatment
There is no cure for lupus, but treatment can control symptoms, prevent flares and protect organs.
Hydroxychloroquine is recommended for nearly all people with SLE. It reduces flares, protects organs and improves long-term survival.
Non-steroidal anti-inflammatory drugs (NSAIDs) can relieve joint pain and mild inflammation.
Corticosteroids such as prednisolone quickly control inflammation during flares. Doctors aim to use the lowest effective dose for the shortest time because of their long-term side effects.
Immunosuppressants such as azathioprine, mycophenolate and methotrexate are used for more serious disease or to reduce the need for steroids.
Biologic medicines such as belimumab and anifrolumab target specific parts of the immune system and are used for people whose lupus remains active despite standard treatment.
Living with Lupus
Alongside medical treatment, several everyday measures help:
- protecting the skin from the sun with sunscreen, hats and covering clothing
- not smoking
- regular, gentle exercise to support joints, heart and mood
- getting enough rest and pacing activities to manage fatigue
- keeping up with vaccinations, after checking with a doctor, since lupus and its treatments can increase infection risk
- attending regular check-ups, including blood and urine tests, even when feeling well
- The Bottom Line
Lupus is a complex, lifelong condition, but it is far more treatable than it once was. With early diagnosis and consistent treatment, most people with lupus live full lives with a normal or near-normal life expectancy. Anyone with a combination of unexplained fatigue, joint pain, rashes and fevers should see a doctor.