CASE REPORT
A 56-year-old female patient presented to our dermatology clinic with a 4-year history of a painful bilateral dermatosis affecting the pretibial region. Lesions slowly progressed from erythematous macules and patches to hard plaques, which gradually disseminated to the anterior and posterior aspect of both lower extremities. The patient referred that within the past 2 months bullae had appeared over the previous sclerotic plaques and that these ruptured inducing ulcer formation. She had received multiple treatments prescribed by general surgeons such as systemic antibiotics, compression therapy, and Unna Boots, without clinical improvement. Physical examination was remarkable for atrophic plaques with erythematous borders some of which presented bullae on their center and impetiginized crusts (Figure 1). Lesions affected both legs and thighs. She denied any history of trauma, autoimmune diseases, malignancies, diabetes, hypertension, thyroid, or renal disease. Histopathological examination of skin biopsies revealed hyperkeratosis, atrophic epidermis, and a subepidermial blister with fibrinous content. The dermis underneath showed marked fibrosis, absence of skin appendages and a minimal superficial lymphocytic infiltrate (Figure 2). Necrobiotic changes in dermal collagen were absent and colloidal iron stain was negative for mucin deposition. Laboratory studies were non-contributory for systemic autoimmune disease. Diagnosis of bullous morphea was established after clinicopathological correlation. The patient was started on psoralen plus ultraviolet A therapy (PUVA), along with prednisone (0.5 mg/kg/day) but the disease was unresponsive after 32 phototherapy sessions and was therefore switched to UVA-1. After 16 UVA-1 sessions lesions worsened and light therapy was interrupted. Treatment with methotrexate 20 mg/ week, deflazacort (0.5 mg/kg/day), and topical betamethasone dipropionate with calcipotriol was initiated. Multiple recurrent episodes of bullae formation were recorded on her follow-up and after reaching an accumulated dose of 1.5 g this therapeutic approach was stopped. We decided to start mycophenolate mofetil 3 g/ daily and substantial resolution of sclerotic plaques and blistering was obtained after 8 weeks (Figure 3). Mycophenolate mofetil dose was subsequently reduced to 2 g/ daily and deflazacort was slowly tapered to 6 mg/day. After a 3-year follow-up of continuous treatment disease progression has stopped with no major adverse events.
DISCUSSION
Bullous morphea is an infrequent clinical variant of localized scleroderma characterized by the formation of bullae on or around sclerotic morphea plaques. It is a rare disease with about 67 cases reported to date. A recent study on 137 patients with localized scleroderma over an 11-year span showed that only 2 cases were compatible with bullous morphea.1Diagnosis of this entity relies on clinicopathological analysis. Histopathologic characteristics that support the diagnosis include an atrophic epidermis, marked dermal fibrosis, a superficial or deep perivascular lymphocytic infiltrate, collapsed or dilated lymphatic vessels, and areas of subepidermal cleavage.2
