Subacute cutaneous lupus erythematosus

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Background: Subacute cutaneous lupus erythematosus (SCLE) is a

nonscarring non–atrophy-producing photosensitive dermatosis. SCLE may

occur in patients with systemic lupus erythematosus (SLE), Sjögren

syndrome, and deficiency of the second component of complement (C2d),

or it may be drug induced. Some patients also have the lesions of

discoid lupus erythematosus (DLE), and some may develop small vessel

vasculitis.

Patients with SCLE frequently fulfill 4 or more of the criteria used

to classify SLE (see Systemic Lupus Erythematosus). Serologic

abnormalities are common. Therapy with sunscreens, topical

corticosteroids, and antimalarials usually is effective.

Pathophysiology: SCLE occurs in genetically predisposed individuals,

most often in patients with human leukocyte antigen B8 (HLA-B8),

human leukocyte antigen DR3 (HLA-DR3), human leukocyte antigen DRw52

(HLA-DRw52), and human leukocyte antigen DQ1 (HLA-DQ1). A strong

association exists with anti-Ro (SS-A) autoantibodies. The reaction

is believed to be related to ultraviolet (UV) light modulation of

autoantigens, epidermal cytokines, and adhesion molecules, with

resultant keratinocyte apoptosis.

Frequency:

In the US: Worldwide, SLE prevalence ranges from 17-48 cases per

100,000. The highest prevalence of SLE occurs in patients aged 40-60

years. The male-to-female ratio of SLE is approximately 1:10.

The male-to-female ratio of cutaneous lupus erythematosus (CLE) is

approximately 1:2-3. Of patients with CLE, 10-50% have SCLE.

Internationally: No differences in the prevalence of this disorder

are recognized between the US and other countries.

Mortality/Morbidity: Approximately one half of patients with SCLE

have 4 or more of the criteria for classification as SLE, but in

these patients, the disease is less severe, although in individual

patients the full range of severity and end organ dysfunction is

possible. By definition, skin lesions heal without scarring or

atrophy but may leave residual dyspigmentation.

Race: SCLE is more common in Caucasians (85%).

Sex: Male-to-female ratio of SCLE is 1:4.

Age: SCLE typically occurs in patients aged 15-70 years. The mean age

is approximately 43 years.