What is subacute cutaneous lupus erythematosus?
Subacute cutaneous lupus erythematosus (SCLE) is a form of lupus erythematosus of the skin. It is less common than chronic discoid lupus erythematosus (CDLE). Unlike CDLE, SCLE does not tend to cause scarring or atrophy of the skin.
What does it look like?
SCLE can begin with red, slightly thickened patches, which can later change into ring-shaped patches. These ring-shaped patches are characteristic of SCLE, but this typical form does not always arise — sometimes the patches remain more individual and red. SCLE is often located on the back and shoulders, but other locations such as the face and legs can also be involved.
How does it develop?
There is a certain genetic predisposition to developing SCLE; carriers of certain antigens (HLA-B8, HLA-DR3, HLA-DRw52, HLA-DQ1) have a clearly increased risk. The skin changes are usually triggered by exposure to sunlight, but the use of certain medicines (such as hydrochlorothiazide and ACE inhibitors) can also cause them.
Who gets it?
As with many autoimmune conditions, women are affected more often than men (about 80% of patients). First signs can appear at any age, with an average around 45; SCLE in young children is very rare.
SCLE and SLE
About 50% of SCLE patients also meet the criteria for SLE (the more dangerous systemic form of lupus erythematosus). Patients with a combination of SCLE and SLE may develop a relatively milder form of SLE, though this view is not undisputed.
How is it treated?
One of the most important parts of treatment is good protection against sunlight. Limited SCLE of the skin can often be well controlled with a strong corticosteroid cream or ointment (class 3 or 4). When this is insufficient, the doctor can prescribe antimalarials such as hydroxychloroquine. Smokers should stop, because the medication works less well in smokers. In exceptional cases, when standard therapy does not work, treatment with dapsone, retinoids or immune-suppressing medicines can be considered.
Lifestyle and check-ups
Because sunlight (and other UV sources) can trigger the changes, good sun protection is important, and the use of medicines that can trigger SCLE should be avoided. It is important to visit the dermatologist regularly to check that the SCLE is not progressing towards systemic lupus erythematosus; with stable SCLE, a check-up at least twice a year is advised, including blood tests for organ function and autoimmune antibodies. SCLE can eventually burn out on its own.
When to see a doctor
See a doctor for persistent red or ring-shaped patches on sun-exposed skin, so SCLE can be confirmed, treated and monitored for a possible systemic form.