Family doctor

What is it and what causes it?

SLE is described as an 'autoimmune disease' - that is, one in which the body's immune system acts against itself. This results in the production of a variety of antibodies, but instead of being directed against invaders such as bacteria, they are autoantibodies - that is, directed against microscopic structures of the body itself.

The autoantibodies form complexes that circulate throughout the body, causing inflammation within various organ systems, including the skin, kidneys and blood vessels, amongst others. Consequently, SLE is a multi-system disease, with many different symptoms and signs, depending on the organs systems affected.

Although many organs can be affected, most patients with the condition do not have a severe form of the disease.

The natural course of SLE is characterised by 'flares' with periods of disease remission in between. Serious complications (from inflammation in major organ systems) are rare, and nowadays most patients have a normal life expectancy.

The exact cause of SLE is unknown, although genetic defects in the immune system may be involved to some extent.

Who gets SLE?

Although both sexes may develop SLE, it mainly affects young women of childbearing age (being 9 times more common in women than men). It is a rare disease, although the prevalence varies in different races, with a higher frequency in Polynesians, Asians and people of African descent.

How do I know if I have it?

Because SLE affects many organ systems, it may cause a variety of symptoms, many of them non-specific or typical of other diseases characterised by inflammation (e.g. rheumatoid arthritis). However, SLE should be suspected in anyone who has multi-system inflammatory illnesses - especially aching joints (arthralgia), skin disorders (e.g. malar rash [see below]) and fatigue - and has a positive ANA test (see below).

Some of the typical symptoms and signs that may occur in SLE are as follows:

Musculoskeletal disorders

• Arthritis/arthralgia: generalised aches, morning stiffness, but little joint swelling.
• Some patients (~20%) may eventually develop distortion of the hands from affected tendons.
• Bone problems: a minority of SLE sufferers may develop bone necrosis (especially in the 'ball' at the top of the femur [thigh bone]).

Skin/hair disorders

• Classic malar rash: butterfly rash over the cheeks and bridge of the nose, with sparing of the folds of the nose. Usually occurs after exposure to sunlight, and lasts for several days or weeks.
• Discoid rash: red scaly patches.
• Rapid hair loss during active disease. Hair does regrow during disease remission, unless scalp is scarred.

Heart and lung disorders

• Chest pain from pleurisy (inflammation of the covering of the lungs) or pericarditis (inflammation of the covering of the heart).
• Shortness of breath/cough if the lungs are affected (which occurs only rarely in SLE).

Kidney disorders

• Kidney problems occur in up to 50% of patients at some stage during their disease, but usually does not cause any symptoms at first.
• Is severe (causing renal failure) in <5% of sufferers.

Other

• Chronic fatigue, becoming severe when disease flares up.
• Mouth ulcers and occasionally ulcers of the nose or vagina. Self-limiting; may be painless.
• Eye pain and/or redness, visual problems.
• Headaches: may be severe and unresponsive to simple painkillers, although such 'lupus headache' is uncommon. Migraine or tension headaches are more common.
• Delirium: uncommon.
• Raynaud's phenomenon: symmetrical pallor of the fingers in response to cold. Fingers then become blue and finally return to pink.
• Fever: may be due to disease activity or to concurrent infection.

What will my doctor do?

If your doctor suspects that you may have SLE, various blood tests will be done to confirm the diagnosis. A full blood count will be taken to look for anaemia and to measure disease activity. In addition, levels of various autoantibodies that have been recognised in SLE will be measured. The most common of these is the antinuclear antibody (ANA). Coagulation studies may be performed, to measure the clotting ability of the blood; abnormalities are associated with increased risk of clots (thrombosis).

A urine specimen will be analysed for evidence of early kidney disease. Dipsticks of the urine should be performed regularly to monitor the effects of SLE on the kidneys.

Depending on the symptoms, x-rays or other imaging procedures may be required.

Patients with suspected SLE are usually advised to see a specialist for advice with management of the disease.

How is it SLE treated?

Unfortunately, SLE has no specific 'cure', so management focuses on prevention of lupus flares, and treatment of symptoms.

Prevention of flares

Patients should ensure they have adequate sleep, and avoid fatigue.

Sufferers should avoid sunlight (and sun-beds) as it may cause characteristic skin rashes and induce a generalised flare. Patients should use broad-spectrum sunscreens of at least SPF 15, and should wear long sleeved clothes and sun hats.

Female patients should be careful in their choice of oral contraceptive (OC): those with mild SLE may use a low-oestrogen combined OC. However, those with severe disease should avoid them, as should patients who have migraine headaches, raised blood pressure, a history of thrombosis, or raised levels of a particular autoantibody; a progestogen-only OC ('mini-pill') is suitable in these patients. Intrauterine contraceptive devices should not be used, as there is an increased risk of infection. Older patients requiring hormone replacement therapy should have it managed and monitored by their specialist.

Infection may precipitate a flare in SLE, and may be life-threatening. Thus, any flu-like illness or fever of more than 1-2 days duration should prompt a visit to the doctor.

Symptomatic and supportive treatment

There are many medications available for the treatment of SLE symptoms, with common anti-inflammatory drugs (e.g. ibuprofen) being useful for arthralgia, headaches and fever.

Disease modifying drugs are used to suppress disease activity. Corticosteroids such as prednisone are used to suppress SLE flares and have transformed the lives of sufferers. However, because of their various side-effects, steroids should be slowly reduced once a flare has been controlled. Some patients may require continuous low-dose steroid treatment for maintenance.

Skin, hair and joint disorders may be treated with drugs used in malaria (e.g. hydroxychloroquine). Immunosuppressive drugs are used for life-threatening diseases of major organs (such as the kidneys or brain). There are various agents available; they require specialist supervision and frequent monitoring for side-effects.

Occasionally, kidney disease may be so progressive that dialysis or kidney transplant is required. After dialysis or transplant, there is often a reduction in disease activity and flares; recurrence of kidney disease is uncommon in the transplanted organ.

Am I going to recover?

As noted earlier, SLE is generally characterised by remissions and flares, although some patients may have a spontaneous permanent remission. With modern treatment options (including dialysis), the long-term outlook for sufferers has improved greatly, and almost 90% of sufferers are still alive 10 years after the diagnosis. The prognosis is worse in patients who are non-white, male and either very young or very old.

SLE has implications for patients wishing to become pregnant. Although the disease does not affect fertility, pre-existing kidney disease may worsen during pregnancy. In addition, there may be flaring of the disease in the third trimester (last 13 weeks of pregnancy). There is also increased risk to the baby: miscarriages in the second trimester are more common in patients with specific types of autoantibodies. Pregnancy in SLE patients should thus always be monitored in specialist units.

Getting help

Because of the complexity involved and the importance of making a correct diagnosis, it is advisable to have an initial review with a specialist (rheumatologist) to confirm the diagnosis and plan appropriate treatment.