Bullous systemic lupus erythematosus_1212 Derm Dx
A 17-year-old black female presented to the dermatology clinic complaining of acute onset of blisters. The lesions appeared first on her face but were rapidly progressing to other areas of her body. Some rested on erythematous bases, while others had no associated erythema.
Most of the lesions were discrete, but some had coalesced into larger bullae. The patient’s overall health was good. She reported no relevant personal or family medical history.
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The diagnosis was bullous systemic lupus erythematosus (BSLE), a unique presentation of systemic lupus erythematosus (SLE). Roughly 23% of patients with SLE present with cutaneous lesions; 66% will have skin lesions at some stage of their disease. Fewer than 5% will have vesiculobullous lesions.
Most, but not all, BSLE patients will meet American College of Rheumatology (ACR) criteria for SLE at the time of diagnosis. Some will go on to meet all ACR criteria for SLE later in the course of their dermatologic disease
The diagnosis of BSLE is usually confirmed by biopsy showing a subepidermal bulla with abundant neutrophils stuffing the dermal papillae and lined up single-file along the dermal-epidermal junction.
The course of the vesiculobullous eruption is generally un-related to the severity of the systemic manifestations of the patient’s SLE. The presenting blisters are tense and may be-come confluent. The eruption is commonly widespread.
Bullous skin lesions may appear on both flexural and extensor surfaces, with some preference for sun-exposed areas. The blisters may arise on an urticarial base or on normal skin. Some patients demonstrate clusters of small blisters.
Oral manifestations are present in approximately 30% of BSLE patients. Prompt treatment usually prevents scarring, but lesions do cause hyperpigmentation that can last for years. The hyperpigmentation responds poorly to treatment, and for many dark-skinned patients, it can be devastating.
BSLE typically presents in the second and third decades of life. Patients seldom have discoid lesions. Antibodies to type VII collagen are commonly detected. The eruption is often resistant to oral corticosteroids but responds dramatically to antineutrophil drugs, such as dapsone and colchicine.
Patients at risk for glucose-6-phosphate dehydrogenase (G-6-PD) deficiency may experience severe hemolysis with dapsone, so some dermatologists use colchicine until G-6-PD testing results are known. The most common side effects of colchicine are transient diarrhea and abdominal discomfort.
When initiating dapsone therapy, obtain baseline complete blood counts and liver function tests and repeat weekly during the initial treatment period. Adverse reactions to dapsone include an idiosyncratic hypersensitivity, which generally begins four to six weeks after initiation of treatment and can result in hepatic necrosis. A measleslike rash, fever, malaise, and lymphadenopathy suggest a diagnosis of dapsone hypersensitivity. The dapsone should be discontinued immediately; most patients will require high-dose corticosteroids.
Azathioprine, antimalarials, and cyclophosphamide have been useful in patients unresponsive to dapsone.
Our patient’s biopsy was typical of BSLE. An antinuclear antibody titer was 1:160 and anti-DNA was 1:265. She had arthralgia but no visceral involvement related to her lupus.
Treatment with oral corticosteroids had no effect, but the lesions responded promptly to colchicine at a dose of 0.6 mg b.i.d. She was switched to dapsone for maintenance therapy but was switched back to colchicine when she developed a dapsone hypersensitivity reaction (pruritic morbilliform eruption, nausea, and abdominal pain with elevated liver enzymes). The plan is to continue therapy until there is re-mission. This commonly occurs after a period of months.
Dirk M. Elston, MD, is president of the American Academy of Dermatology and director of the Ackerman Academy of Dermatopathology in New York.