Introduction

Lupus, also known as systemic lupus erythematosus (SLE), is an autoimmune disease where the body's immune system attacks its own tissues and organs.

Diagnosing lupus can be notoriously difficult and complex, because the symptoms of the condition are varied and involve multiple areas of the body, and a wide age range of patients are affected.

For example, skin rashes, joint pain, problems with kidney function, chest pain and even heart problems can be symptoms of lupus, but linking them together for a definitive diagnosis can be difficult.

If you're wondering how lupus is diagnosed, and which blood tests, examinations, or scans you might need to find out if you have lupus, this guide will explain all you need to know.

What is Lupus, and how do you get it?

Lupus is an autoimmune condition, which means the function of the immune system is abnormal, causing the body to attack and even destroy its own healthy tissues and organs.

Systemic lupus erythematosus is more common in women than men, and is generally diagnosed between the ages of 15-45. Like some other autoimmune diseases, little is known about the cause of lupus, but it is believed to be triggered by a combination of genetics and environmental factors such as excessive sun exposure, use of certain prescription drugs, and infections. People who are of Hispanic, Asian or African descent may also have an increased risk of developing lupus.

Cutaneous lupus erythematosus (CLE) is a type of lupus that manifests as a skin disease, with symptoms including a skin rash, hair loss, sun sensitivity and mouth ulcers.

Neonatal lupus is a condition in babies where antibodies have been passed from mother to baby during pregnancy. While neonatal lupus often goes away within a few months with no lasting consequences, it is likely that the mother will develop lupus later in life.

What are the main symptoms of lupus?

Lupus causes inflammation as the immune system attacks healthy tissues. This can lead to a range of symptoms that can affect one, or multiple, areas of the body.

These include:

Rashes, which can be triggered by sensitivity to sunlight, or mouth sores.
Extreme fatigue or tiredness, which doesn't ease even if you rest.
Joint pain, muscle pain, tendonitis or tendon rupture, and even arthritis.
Dizziness, headaches, vision problems or even seizures caused by inflammation in the brain and central nervous system.
Blood clots, excessive bleeding, inflamed blood vessels, or even anaemia caused by reduced numbers of healthy red blood cells.
Chest inflammation, pneumonia, chest pain or heart inflammation, which can cause an increased risk of cardiovascular disease and heart attacks.

How is systemic lupus erythematosus diagnosed?

Medical history

A doctor will usually assess your medical history. As lupus has many symptoms that can be similar to other conditions, an assessment of any previous medical complaints will help a doctor link them together and see if lupus is suspected. Also, lupus can range in severity from mild joint and skin issues to severe inflammation of vital organs, including heart, lung and kidney problems, so an understanding of any previous problems will help guide their diagnostic thinking.

Blood tests and lab tests

As lupus is linked with anaemia, your doctor may request a complete blood count test to measure the number of red and white blood cells, haemoglobin and platelets. A positive test for anaemia or low white blood cell count can be signs of lupus.

ANA (antinuclear antibody) tests can show the presence of certain antibodies produced by the immune system, which can be a sign of lupus. While many people with positive ANA test results won't have lupus, if you test positive it can direct your healthcare professional towards other tests.

Kidney disease and reduced liver function can be caused by lupus, and blood tests can assess their function, along with urine tests, which may also be advised.

Biopsy

If your doctor suspects kidney disease or kidney problems due to initial blood or urine tests, they may request a kidney biopsy. This is a surgical procedure where samples of kidney tissue are taken and analysed in laboratory tests to identify any kidney damage and possible treatments.

Can imaging like ultrasound, X-ray or MRI be used to diagnose lupus?

90% of lupus patients have musculoskeletal symptoms or associated rheumatic diseases, such as arthritis, joint pain, muscle tenderness or pain, and tendon inflammation or rupture. This can significantly affect the day-to-day well-being of lupus patients, and can limit their ability to work and carry out normal activities.

Diagnostic imaging techniques such as ultrasound may be recommended if lupus is suspected, as they can help identify these problems that are closely linked with lupus. Ultrasound is safe and noninvasive, and is usually the first imaging test that would be suggested.

Overlapping symptoms of rheumatoid arthritis and lupus (SLE) has been coined 'Rhupus,' which is a rare combination of erosive arthritis and systemic lupus erythematosus.

Osteonecrosis is a more severe symptom of lupus, and can happen when blood flow to a certain part of a bone is disrupted. This can cause the healthy tissue to die and break down, causing fractures or collapse of a joint. Examples of joints include the wrist, hip, knee, shoulder, ankle and elbow.

This is why symptoms like joint pain should be investigated in patients with suspected lupus, as the earlier osteonecrosis is identified, the better the options for treatment are. MRI is the best imaging technique to identify osteonecrosis, and this may form part of a lupus diagnosis and treatment pathway, along with ultrasound for more general investigations into soft tissue and musculoskeletal symptoms of lupus.

Lupus can also cause heart problems and lung issues such as inflammation or fluid on the lungs. Therefore a chest X-ray or echocardiogram for the heart might be recommended.

Is it possible to treat lupus?

If you receive a lupus diagnosis, it can feel overwhelming, but there are some treatments available and some recommended lifestyle changes that can support a healthy lifestyle with lupus.

Treating lupus

Lupus symptoms flare up and retreat in many people, and medication is important to manage symptoms and control lupus flares. Example medications include:

Nonsteroidal anti-inflammatory drugs to treat pain and swelling
Steroids to counter inflammation
Immunosuppressants to suppress the immune system's attack on healthy tissues synonymous with an autoimmune disorder.
Antimalarial drugs can reduce the severity of lupus flares, despite being initially designed to treat malaria.

There are also promising clinical trials using voclosporin to treat lupus.

It is important to note that many lupus medications do have side effects, which need to be carefully considered by you and your healthcare provider.

It is also worth noting that some lupus medications can cause pregnancy complications, and women with lupus generally have an increased risk of high blood pressure during pregnancy and even miscarriage. It is important to take to your doctor if you plan on becoming pregnant, as they might recommend waiting six to twelve months while you monitor lupus symptoms and response to medication.

Lifestyle changes to help manage symptoms

With your doctor's guidance, there are many lifestyle changes you can make to help manage lupus and prevent your symptoms from worsening.

Examples include:

Quitting smoking, or not starting to smoke, to improve your overall health and reduce further risk of heart disease, lung conditions and other smoking-related health concerns.
Reducing sun exposure, wearing high-factor suncream, and wearing a hat when in the sun.
Eating a healthy diet, taking supplements where required, and staying active where you can.

Next steps

If you've been recommended a scan to identify issues associated with lupus, or are concerned about your syptoms, you can book online today.
Visit our news page for more information about the role of diagnostic imaging for a range of health conditions.

Sources used

https://www.mayoclinic.org/diseases-conditions/lupus/symptoms-causes/syc-20365789

https://www.cdc.gov/lupus/basics/women.htm

https://www.jrheum.org/content/50/3/456

https://pubs.rsna.org/doi/abs/10.1148/rg.244985082?journalCode=radiographics

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8285327/

https://www.nhs.uk/conditions/lupus/

https://www.niams.nih.gov/health-topics/osteonecrosis

How Is Lupus Diagnosed? Your Guide to Lupus Symptoms, Tests, Scans, and Treatments