Subacute cutaneous lupus (SCLE) is a type of lupus that causes skin rashes. It’s usually triggered by sun exposure and can be caused or worsened by certain medications, such as proton pump inhibitors or calcium channel blockers.

SCLE is a subtype of cutaneous lupus erythematosus (CLE). CLE is a form of lupus that primarily affects the skin, causing rashes and sores that can be painful and itchy. SCLE accounts for 8% of all cases of CLE.

SCLE can affect anyone, but it may be more common in certain populations, such as women. About half of the people with SCLE usually have systemic lupus (SLE). Some people with SCLE also go on to develop SLE.

SLE is an inflammatory disease in which the immune system starts attacking healthy tissue and organs. These can include the kidneys, heart, lungs, or nervous system.

SCLE is also associated with other conditions, including Sjögren disease. Read on to learn more about SCLE, symptoms, causes, and treatment options.

SCLE is a subtype of CLE. It can also affect people who have systemic lupus (SLE). This means someone could have an SCLE rash, then go on to develop other symptoms of SLE that don’t affect the skin, such as kidney issues. Other types of CLE include:

  • acute cutaneous lupus
  • chronic cutaneous lupus

SCLE primarily affects the skin, causing ring-shaped sores, rashes, or patches that can be painful or itchy. These rashes can be red, but they can also appear purple or dark brown on darker skin tones. Unlike the chronic type, SCLE does not cause skin scarring or discoloration.

SCLE is also different from acute lupus, which distinguishes itself through a rash that appears across both cheeks and on the bridge of the nose, typically called “butterfly rash” or “malar rash.” This slightly raised rash can appear red on lighter skin or purple and dark brown on darker skin tones.

SCLE rashes don’t typically appear on the face or scalp. They usually occur across the body, on the back, arms, chest, or torso.

This rash can also appear during a flare-up of SLE.

The most common symptoms of SCLE include rashes on different body parts that are usually exposed to sunlight, such as the arms, back, chest, or torso. You may notice that your rashes can appear:

  • ring-shaped
  • swollen
  • red
  • purple
  • dark brown
  • bumpy
  • dry

You may also experience some skin discoloration once the rash goes away.

SCLE can occur on its own or as a complication of SLE. SCLE can also happen after taking certain medications, such as calcium channel blockers or proton pump inhibitors, for a long period of time.

About one-third of all cases of SCLE are triggered by drugs. Symptoms may begin months or years after use of these medications. Examples of these include:

Other drugs reported as triggers for SCLE include:

Environmental factors such as exposure to ultraviolet light also play a role in increasing the risk of flare-ups.

A specialist, such as a dermatologist or a rheumatologist, will typically diagnose the condition. During your appointment, they may ask about your:

  • symptoms
  • medical history
  • family history
  • medications

They may also perform a physical examination and check your skin for rashes and sores. To further get an idea of your condition, they might request certain tests such as:

  • urinalysis
  • blood tests to check for certain proteins in your blood
  • biopsy, to assess a sample of affected skin in the laboratory
  • lupus band test, to take a sample of your unaffected skin and test it

Treatment for SCLE usually involves lifestyle strategies and medications when necessary. Exposure to sunlight can trigger SCLE, so it’s very important to limit time in the sun to avoid worsening or triggering symptoms.

If you go outside, try to always wear a broad-spectrum sunscreen with at least SPF 50, as well as a wide-brimmed hat or other protective clothing that can shield you from the sun.

Your doctor might also prescribe medications such as topical corticosteroids to apply to the affected areas. Oral or systemic corticosteroids should typically be avoided, unless you only need to use them for the short term to relieve symptoms during a flare-up.

You might also receive antimalarial medications to help with the symptoms, although it’s important to note that these drugs are less effective in people who smoke.

Other medications your doctor might recommend for SCLE include:

SCLE is not curable, but treatments are available to manage the condition and ease symptoms. Lifestyle modifications can also help prevent flare-ups.

If taking certain medications is causing SCLE, then stopping the drugs should resolve the condition. You should stop experiencing any symptoms a few weeks or months after discontinuation of these medications.

Rashes and sores caused by SCLE don’t typically scar the skin, but they may cause some skin discoloration. However, in most cases, discoloration is not permanent.

Limiting sunlight is important in order to prevent triggering symptoms, so healthcare professionals recommend supplementing with vitamin D and calcium to avoid deficiency.

Consult with your doctor before taking any supplements. They can order a vitamin panel and decide whether supplementation is necessary for you specifically.

Some people with SCLE may also go on to develop SLE. This means other organs in the body, such as the kidneys, lungs, or nervous system, might be affected.

SCLE is a subtype of lupus that affects the skin, causing red, ring-shaped rashes. These commonly occur on the back, arms, torso, or areas of your skin that are commonly exposed to the sun.

Exposure to sunlight is a common trigger for SCLE, so it’s important to minimize time spent outdoors or wear sun-protective clothing and sunscreen when you do go out.

Reach out to a doctor or healthcare professional if you notice rashes on your skin and think you might have SCLE.