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AlexanderSalava

Discoid Lupus Erythematosus

  • This article addresses the type of lupus erythematosus that is mainly confined to the skin (DLE). See also the article Systemic lupus erythematosus Systemic Lupus Erythematosus (Sle).

Essentials

  • Photosensitivity may be due to DLE.
  • Diagnosis is based on clinical presentation and histological examination of a skin biopsy.
  • Management consists of symptomatic treatment and prevention of exacerbations.
  • The possibility of systemic lupus erythematosus (SLE) should be considered.
  • Cutaneous manifestations are encountered in all main types of lupus disease: DLE, subacute cutaneous lupus erythematosus (SCLE) and SLE.

Definition, aetiology and epidemiology

  • A chronic photosensitive autoimmune disease, which may cause permanent scarring on the skin
  • Aetiology is unknown but hereditary factors play a part in disease appearance.
  • More common in women, age of onset generally between 20 and 40 years

Disease types

  • In lupus confined to the skin, other clinical subtypes have been described in addition to the most common discoid (DLE) type.
  • DLE must be differentiated from SLE, which is associated with systemic symptoms.
  • SCLE is a subtype of DLE with reddish and scaly lesions mainly on the upper body and mild systemic symptoms (pictures 1 2).
  • Overlapping is noted when only the cutaneous manifestations of lupus diseases are evaluated.
    • 10-20% of patients with SLE present with cutaneous symptoms suggestive of DLE.
    • 5-10% of patients with DLE may develop SLE with time.
  • The different types of lupus diseases are distinguished with the aid of clinical presentation, systemic symptoms and laboratory investigations (antinuclear antibodies).

Clinical presentation

  • Skin lesions are visible on areas exposed to the sun (face: pictures 3 4; scalp: pictures 5 6; neck, upper chest; backs of the hands, arms).
  • DLE may have many clinical manifestations, and the course of the disease may be variable.
  • Exacerbations are usually seen in the spring and summer.
  • The typical plaques are clearly demarcated, the size of a finger tip, reddish and scaly; as they develop they may atrophy in the middle and scar the skin.
  • The lesions are usually asymptomatic, but they may present with pruritus or tenderness.
  • The lesions often develop 1-2 weeks after sunlight exposure.
  • On the scalp, DLE may cause scarring alopecia (see Hair Loss and Balding), which may have significant aesthetic implications.
  • Rarely causes ulceration in the oral mucosa (picture 7).
  • Some patients exhibit systemic symptoms, such as fatigue, myalgia, arthralgia, slight fever and laboratory tests may show abnormalities (see below).
    • In these cases, the symptomatology may overlap with that of SLE and other connective tissue disorders. The full criteria for SLE are usually not fulfilled.

Diagnosis

  • Based on clinical presentation as well as histological and immunofluorescence tests of a skin biopsy
  • Fungal samples (for culture and microbiology) of single lesions may be indicated to exclude tinea.
  • SLE may produce similar skin lesions and must be excluded with the aid of patient history, physical examination and laboratory tests.
    • Full blood count, CRP, ESR
    • Creatinine, ALT, alkaline phosphatase
    • Urinalysis
    • Serum antinuclear antibody analysis, antibodies to extractable nuclear antigens, DNA antibodies
    • Plasma C3 and C4 complement levels
  • Any systemic symptoms are investigated using appropriate laboratory tests and imaging techniques.
  • The results may be positive for antinuclear antibodies (the ANA test is positive in 5-10% of patients) and show blood picture changes (leucocytopenia, thrombocytopenia) even in cases where the disease is confined to the skin.
  • Typical autoantibody profiles may be seen in connective tissue disorders.
  • Diagnosis can never be made based on antibody tests alone, and overlapping between the diseases occurs.
    • A positive test result for SSA antibodies and SSB antibodies (Sjögren's syndrome antibodies), may be suggestive of SCLE.
    • Positive test results for DNA antibodies, ribonucleoprotein antibodies and Smith (Sm) antibodies are suggestive of SLE.

Differential diagnosis

  • Skin changes due to SLE Systemic Lupus Erythematosus (Sle) (discoid skin lesions, butterfly rash)
  • Polymorphous light eruption: recurring, small pruritic papules on the chest and backs of the hands in the spring, appearance directly linked to the time elapsed from sun exposure
  • Drug-induced photodermatitis and other photodermatitis Photodermatitis
  • Rosacea Rosacea: papules and pustules, telangiectasia, lesions only on the face
  • Psoriasis Psoriasis: typical sites of predilection, nail involvement
  • Tinea Dermatomycoses: isolated lesions with scaling around the borders

Treatment Drugs for Discoid Lupus Erythematosus

  • The treatment of general symptoms follows the guidelines given for SLE Systemic Lupus Erythematosus (Sle).
  • Treatment aims to eliminate symptoms, control the active disease, prevent exacerbations, minimise drug adverse effects as well as to improve the quality of life.
  • Active skin lesions require effective management in order to prevent scarring of the skin and consequent cosmetic issues.
  • Avoidance of the sun's UV radiation by wearing correct clothing and using sun screens may prevent the development of new lesions.
  • Less aggressive lesions can be treated with topical therapy.
    • An adequately long treatment period with moderately potent to potent glucocorticoid creams, for example once daily in the evening for 2-3 weeks, thereafter twice a week for 1-2 months as required.
    • Tacrolimus cream is also a good choice, for example twice daily until the rash has started to subside, thereafter twice a week as required.
  • Systemic treatment
    • The first-line treatment is hydroxychloroquine. Regular laboratory monitoring is recommended during the treatment (full blood count, ALT) as well as check-ups by an ophthalmologist (before treatment if needed and then every 5 years).
    • Oral glucocorticoids may be considered as short term treatment in a severe exacerbation, for example prednisolone 30-40 mg in the mornings whilst tapering the dose down over 2-4 weeks.
    • Other treatment alternatives include immunosuppressive medication prescribed under the supervision of a dermatologist or rheumatologist (e.g. methotrexate, azathioprine, mycophenolate mofetil or dapsone, thalidomide or retinoids).

Specialist consultation and monitoring

  • The diagnosis and treatment of DLE are the responsibility of a dermatologist.
  • In mild disease forms, the monitoring may be carried out in primary health care.
  • Treatment response may show great variation, and the disease may reactivate after many years of remission.
  • If SLE is suspected, a referral to a specialist in internal medicine or a rheumatologist is required.

Evidence Summaries ⬆