October 2005

Fig.4

Physical examination:
Multiple tense bullae on normal and erythematous skin on her face, eyelids, lips, neck, arms, hands, dorsal feet, abdomen and pubic area. Multiple crusted erythematous plaques and erosions on her face, hands, feet and neck. She also had bullae and targetoid lesions on her palms and soles (Figures 1, 2 and 3).

Histopathology:
Subepidermal bulla with a neutrophilic infiltrate at the base. (Figure 4)

Direct immunoflourescence:
Linear, granular basement membrane zone positivity for IgG, C3 and IgM and negative for IgA.

Diagnosis: Bullous Lupus Erythematosus

Discussion:
The patient was maintained on plaquenil and her prednisone was increased to 1mg/kg/day. She responded well to this therapy with cessation of blister formation and gradual resolution of her existing bullae. After confirming that she expressed normal G6PD levels she was started on dapsone and the prednisone was slowly tapered.

Bullous lupus erythematosus is a rare subset of systemic lupus erythematosus (SLE). Approximately three-fourths of patients with SLE will have skin lesions and fewer than 5% of these patients will have bullous lesions. It generally presents in the second or third decade of life.Bullous lupus erythematosus is characterized by widespread, nonscarring, subepidermal blisters in patients with SLE. The lesions typically occur on sun exposed skin and have no predilection for flexural or extensor surfaces. The bullae may form on normal or erythematous skin and can resemble bullous pemphigoid. Approximately 30% of the cases present with oral lesions, especially on the vermilion boarder.
Histologically, bullous lupus erythematosus is characterized by neutrophil-rich, subepidermal bulla. There are often neutrophils along the dermal-epidermal junction and papillary microabcess formation. Immunohistologically, it resembles LE with immunoglobulins and complement components deposited in a linear-granular pattern along the dermal-epidermal junction. Bullous lupus erythematosus is often associated with an autoimmunity to type VII collagen.
Bullous lupus erythematosus lesions may last for weeks to months and may spontaneously wax and wane. The lesions respond to treatment with corticosteroids, antimalarials, azathioprine and cyclophosphamide. However, the bullae generally also respond well to dapsone. The prognosis of patients with bullous lupus erythematosus is predicated mainly by the systemic involvement of their SLE.

References:
Fitzpatrick's Dermatology in General Medicine. Freedberg, IM, Eisen, AZ, Klaus, W, Austen, KF, Goldsmith, LA, Katz, SI. New York, McGraw-Hill, 2003, pg 1686.

Harris-Smith R, Erickson QL, Elston DM, David-Bajar K. Bullous Eruption: A Manifestation of Lupus Erythematosus. Cutis 2003; 72: 31-37.