Lupus is a disease of the immune system that causes the body to mistake healthy tissue for a harmful intruder and attack it.
The disease can damage any part of the body. It is defined as chronic, meaning that symptoms occur for a long time or happen repeatedly.
Discoid lupus affects the skin, causing a red, scaly rash with raised borders on areas of the body that are exposed to sunlight.
In this article, we look at the symptoms of discoid lupus, along with its causes and risk factors. We also examine what can be done to diagnose, treat, and prevent the disease.
Image credit: Leonard C. Sperling, M.D., Department of Dermatology, Uniformed Services University, 2009
Research by The National Resource Center on Lupus estimates that at least 1.5 million Americans have lupus.
Systemic lupus erythematosus, or SLE, is the most common form of lupus, affecting joints, muscles, various tissues, and organs in the body.
Cutaneous lupus erythematosus, or CLE, refers to forms of lupus that affect the skin, causing rashes and sores.
Discoid lupus is the most common type of CLE. It is an autoimmune disease, which means that the immune system mistakenly identifies its own tissue as foreign and mounts an attack.
A healthy immune system will fight off viruses and bacteria that can cause illness. With discoid lupus, the immune system attacks healthy skin, causing sores that appear as a disc-shaped rash.
Discoid sores present as a distinctive thick, scaly rash, ranging in color from red to purple.
The rash can appear in one place or a number of areas on the body. It is most likely to appear on areas of the skin that are regularly exposed to sunlight, such as the face, neck, and backs of the hands.
There are usually no other symptoms, but some people may feel pain or an itch within the sores.
There are other skin conditions that can look very similar to discoid lupus, such as plaque psoriasis or eczema. It is important for people to see a doctor to get an accurate diagnosis.
Like all forms of lupus, discoid lupus does not have one clear cause.
It is possible that hormones, genetic factors, and environmental triggers can all play a part in the development of the disease. Examples of environmental triggers include exposure to ultraviolet light and stress.
Groups of people who are more at risk of discoid lupus include:
- people with a family history of lupus or other diseases of the immune system
- women, who make up more than 90 percent of people with lupus
- African-Americans, who are three times more at risk for lupus than Caucasians
- 20-to-50-year olds
Image credit: E. Burgess, Lupus Erythematosus. Chromolithograph. c. 1878-1888, Wellcome Library, London
Lupus can be difficult to diagnose, and discoid lupus will usually get worse without treatment.
People should see a doctor as soon as symptoms appear. They should also aim to keep a record of how symptoms develop and find out if they have a family history of autoimmune diseases.
At a medical appointment, people can expect some or all of the following:
- an examination of the skin
- questions about medical history
- blood or urine tests
- a skin biopsy, where a sample of skin tissue is taken for examination
Any doctor can diagnose discoid lupus. However, they may also recommend that the person sees a dermatologist, a doctor that specializes in diseases of the skin, or even a dermatologist that specializes in autoimmune skin diseases.
A rheumatologist, a doctor that specializes in diseases of the joints muscles and autoimmune diseases, can offer further advice if there is concern that joints or organs may be affected.
The American College of Rheumatology have created a list of common symptoms to support doctors in making a diagnosis of lupus.
There is no permanent cure for discoid lupus.
Treatment aims to prevent new sores, limit scarring, and make the skin look healthier. Without treatment, a discoid lupus rash will often worsen.
Treatment will usually consist of some or all of the following:
- creams or ointments to be applied directly to affected areas of the skin
- injections that contain prescription steroids into or around the lesions
- antimalarial drugs, such as hydroxychloroquine, taken in tablet form
Creams, ointments, and corticosteroid injections all work to reduce the redness of discoid rash, reduce inflammation, and improve the skin’s appearance.
Antimalarial drugs, also classified as mild disease-modifying anti-rheumatic drugs, or DMARDs, are no longer used to treat malaria.
Hydroxychloroquine is one of the medications that can be used to treat discoid lupus if other treatments have been unsuccessful. It should decrease damage to skin over time, reduce the number of times the disease will flare up, and help the body to delay absorbing UV light that can damage the skin.
One of the most important ways to manage discoid lupus, and prevent the discoid rash from getting worse, is to protect the body from exposure to the sun’s harmful UV rays:
- use UVA or UVB sunscreen with a high sun protection factor (SPF) of 50 or above
- wear a wide-brimmed hat when out in the sun
- choose clothing that covers most of the body
Smoking may worsen discoid lupus, or make it harder to manage the condition. Smokers are advised to quit, which has many health benefits.
Like other forms of lupus, discoid lupus is a disease that often flares, with the condition worsening for periods of time. Stress may be a factor in causing a flare, so people should try to look after their well-being and manage stress as much as possible.
Discoid lupus can cause scarring. People who are worried about the appearance of these scars may choose to consider cosmetic surgery, such as laser technology, which can be an option when the symptoms are not flaring.
Discoid rash can cause skin discoloration, scarring, and hair loss if the sores occur on areas where hair grows, such as the scalp. Like any scars, this can be permanent, but prompt treatment should lessen scarring.
Discoid lupus can occur on its own or alongside SLE, the form of the disease that affects many organs in the body. Only around 1 in 10 people with lupus affecting the skin will go on to develop SLE, however.
If people notice symptoms of SLE developing, they may receive a biopsy and further blood tests to confirm a diagnosis.
Discoid lupus can be difficult to diagnose as it may look similar in appearance to other skin conditions. Awareness of lupus is increasing, however, and early diagnosis and treatment should limit the effects of the disease.
Although there is no permanent cure for discoid lupus, there is a lot that can be done to manage the condition.
Taking care of the skin by limiting exposure to sunlight is a simple first step that can have a positive impact.