What is lupus? Debilitating autoimmune illness affecting 5 million people worldwide

Five million – this is the number of people worldwide that may be suffering from a form of lupus. This strange disease takes its unusual name from the Latin word for "wolf" – due to Lupus vulgaris, a severe form of the disease which has nearly disappeared now, appearing to resemble a wolf's bite.

Lupus is a complex condition that is still not very well understood. Different forms of the disease exist, but the most common is known as systemic lupus erythematosus or SLE, the focus of this article. It can affect many parts of the body, including the skin, joints and internal organs.

Lupus is an autoimmune disease, meaning that it is caused by dysfunctions of the immune system. It produces too many antibodies which can attack and inflame healthy cells, tissue and organs anywhere in the body.

What are the symptoms of lupus?

SLE is characterised by a number of symptoms, which makes it difficult to distinguish from other conditions. The most common symptoms include extreme tiredness, rashes, joint pains and swelling. Anaemia, fever, headaches, hair loss and mouth ulcers may all be observed in some patients.

Major organs can also be damaged, sometimes irreversibly – the most at risk being the kidneys, the heart, the lungs and even sometimes, the brain. Depending on the person all these symptoms can range from mild to life-threatening. Life expectancy has improved a lot in the past years and patients can now expect to have a normal lifespan.

Less common forms of lupus that just affect the skin – such as discoid lupus erythematosus and subacute cutaneous lupus erythematosus.

How is it diagnosed?

Lupus is characterised by very diverse symptoms from one patient to another, with different degrees of severity, so a diagnosis is often difficult to reach. Confusion with other illnesses is frequent as the condition shares a number of characteristics with leukaemia, muscular dystrophy and multiple sclerosis.

There are no specific blood tests available to diagnose a person with the disease – rather a number of different blood tests may be carried out to understand what is happening to a patient. The ESR test for instance assesses there is any inflammation in your body, which could be a good symptomatic indication of lupus.

An anti-nuclear antibody test may be used to determine whether people's blood has traces of the anti-nuclear antibody. Since this antibody is present in 95% of people with SLE, it suggests the person may be sick but it is not enough on its own to confirm the diagnosis. The anti-DNA antibody is similar, checking for the presence of anti-DNA antibodies in the bloodstream which are found in 7 patients out of 10.

Once the diagnosis has been established, scans will be conducted regularly to monitor how the disease if affecting the internal organs.

What causes lupus?

Lupus is thought to arise from a complex mix of genetic and environmental factors. In the case of SLE, it has been shown that brothers and sisters of people already diagnosed with the condition are more at risk – a strong case for a genetic link. Some genetic mutations have been identified as making people more susceptible to developing the disease, with most having to do with the regulation of the immune system.

When it comes to identifying possible environmental risk factors, different studies have pointed out that the disease can be triggered by hormonal changes in women or by a number of infectious diseases. The main trigger of lupus is believed to be a sudden change in hormonal activity for instance childbirth, at the menopause or during puberty.

Some medicines can also cause lupus-like side effects.

Who is most at risk?

Statistically, women are much more at risk of developing lupus, and the condition is more common in black and Asian women than in white women. It usually develops in people between the age of 15 and 55 years old.

What are the treatment options?

There is not yet a specific treatment to cure the disease, so patients have to rely on drugs that attenuate the symptoms and improve their living conditions. The most common medicine given to lupus patients are known as non-steroidal anti-inflammatory drugs (NSAIDs) – a painkiller medication that reduces inflammation in the body.

Anti-malaria drugs can also be prescribed as they can help with rashes, joint pains and fatigue. Recently, steroids and immunosuppressants have become crucial and more widely used to improve lupus care for the most severe cases.

Clinical trials to find new drugs are ongoing, and patients can inform themselves on the NHS website and may even choose to participate in some of them.