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A chronic and recurrent disorder primarily affecting the skin and characterized by sharply circumscribed macules and plaques displaying erythema, follicular plugging, scales, telangiectasia, and atrophy.
The cause is unknown. The disease is more common in females, appearing most often during their 30s, but the age range is far wider than in systemic lupus erythematosus.
Symptoms and Signs
Active lesions may persist or recur for years. Initially, they are erythematous, round, scaling papules 5 to 10 mm in diameter, with follicular plugging. They appear most frequently on the malar prominences, bridge of the nose, scalp, and external auditory canals. The lesions may be generalized over the upper portion of the trunk and extensor surfaces of the extremities. Mucous membrane involvement may be prominent--especially mouth ulcers. The lesions of untreated DLE gradually extend peripherally, while the center atrophies. The residual scars are noncontractile. A "carpet tack" invagination of the scales into the dilated follicles may be seen in heavily scaled lesions. Alopecia of the scalp may be widespread, scarring, and permanent. Leukopenia and mild and transitory systemic manifestations, such as arthralgias, are common.
Though the disease is usually limited to the skin, about 10% eventually develop varying degrees of systemic involvement, however, usually this is not gross. A small number of patients with DLE develop chronic synovitis as the sole "systemic" manifestation.
Diagnosis
Since the cutaneous lesions of DLE and SLE may be identical, a patient presenting with typical discoid lesions must be evaluated to determine whether systemic involvement is present. A medical history and physical examination are required to rule out the possibility that this is an early cutaneous manifestation of SLE. Diagnostic studies should include biopsy from the active margin of the lesion, CBC, ESR, tests for antinuclear factors, and renal function studies. Skin biopsy will not differentiate DLE and SLE but will rule out other disorders. Antibodies against double-stranded DNA (eg, DNA-binding test) are almost invariably absent in DLE.
In differential diagnosis, the lesions of rosacea are characterized by pustules and the absence of atrophy. The lesions of seborrheic dermatitis are never atrophic and frequently involve the nasolabial area, which is rarely affected by DLE. Lesions caused by photosensitivity are not atrophic and usually disappear when direct sunlight is avoided. Lymphoma or plaques of sarcoidosis may mimic DLE; biopsy should make the diagnosis. When the lips and oral mucosa are involved, lichen planus and leukoplakia must be ruled out.
Treatment
Early treatment is advisable, before atrophy is permanent. Exposure to sunlight (or ultraviolet light) should be minimized. If necessary, a sunscreen preparation should be applied.
It is usually possible to effect involution of small lesions by applying topical corticosteroid ointments or creams tid to qid; eg, triamcinolone acetonide 0.1 or 0.5%, fluocinolone 0.025 or 0.2%, flurandrenolide 0.05%, betamethasone valerate 0.1%, or betamethasone dipropionate 0.05%. The last may be most effective. Plastic tape coated with flurandrenolide frequently helps with resistant lesions. Individual recalcitrant plaques may respond to intradermal injection of 0.1% suspension of triamcinolone acetonide, but secondary atrophy frequently follows. Excessive use of topical steroids is to be avoided.
Antimalarials, such as hydroxychloroquine 200 mg/day, are very useful in the management of DLE. In resistant cases, higher dosages (eg, 400 mg/day) or combinations (eg, hydroxychloroquine 200 mg/day plus quinacrine [mepacrine] 50 to 100 mg/day) may be required for a few months.
SYSTEMIC LUPUS ERYTHEMATOSUS
Fluid & Electrolyte
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