Cutaneous Lupus Erythematosus

Lupus erythematosus is an uncommon group of skin conditions which typically affect women ages 20 to 50. LE may take various forms.

Discoid lupus erythematosus is the most common form of LE, and consists of the formation of scaly patches of skin which are red in color, typically on the nose, ears, and/or cheeks. The condition and result in pigmentation and scarring of the affected area, and may involve hair follicles, resulting in permanent alopecia in some cases. Subacute LE consists of a dry rash on the upper torso, often after exposure to the sun, which does not scar and may present as ring-shaped, nodules, vasculitis, or scaly bumps. Lupus tumidus affects the dermis, and is distinctive because of its extreme photosensitivity. It consists of red, swollen bumps or patches, similar to hives, which may be ring-shaped. Lupus profundus affects subcutaneous fat, and may affect anyone, including children, and consists of deep, firm nodules typically on the face, resulting in Lipodystrophy. Neonatal LE affects the newborns of mothers with subacute LE, and consists of a temporary rash of similar nature. Chilblain LE may develop in relation to circulatory problems, and is similar in appearance to conventional chilblain. Cutaneous lupus mucinosis is rare and typically occurs as a symptom of lupus tumidus, and consists of small bumps, plaques or nodules on the face, torso or upper arms. Drug induced LE may be caused by certain medications, but symptoms generally do not appear for several months, and do not typically affect the skin. Additionally, cutaneous LE may appear as part of the less common systemic Lupus erythematosus, and consists of a butterfly rash across the cheeks, increased photosensitivity, mouth ulcers, hives, and thinning of hair, in addition to various systemic symptoms.

LE is an autoimmune disorder in which the nuclei of skin cells in the affected area are attacked by the immune system. This response may be triggered by exposure to sunlight, and the condition's effects are more severe in those who smoke. The condition most commonly appears in adult women, but may also develop in males, children, and older persons.

Differential Diagnosis (Other conditions with similar appearance)
Antiphospholipid syndrome
Polyarteritis nodosa
Fibromyalgia
Preeclampsia (Toxemia of Pregnancy)
Hepatitis C
Rheumatic Fever
Infectious mononucleosis
Rheumatoid arthritis
Infective Endocarditis
Scleroderma
Lyme disease
Serum sickness
Lymphoma, B-cell
Thrombotic Thrombocytopenic Purpura
Mixed Connective-Tissue Disease
Undifferentiated Connective-Tissue Disease

LE is diagnosed based on the characteristic appearance of the affected area in conjunction with various laboratory and blood tests. A skin biopsy may be performed to confirm the diagnosis and to rule out similar appearing conditions.