Bullous morphoea: a retrospective study.

Bullous morphoea is a rare variant of localized scleroderma whose pathogenesis has been widely discussed. We retrospectively reviewed the records of all histopathologically confirmed cases of morphoea followed from 2005 to 2015 at the Dermatology Clinic and Pathology Institute of the University of Cagliari, Sardinia, Italy. Among 137 patients with morphoea, 2 cases of the bullous variant were identified, which were successfully treated with methotrexate. Thus, the bullous form comprised 1.4% of all cases of morphoea, which is much lower than the 7.5% previously reported. In one of the cases, histopathological examination revealed a peculiar 'stretching' pattern of basal keratinocytes attached to the epidermal roof of the bulla, together with increased lymphatic vessels, which were either collapsed or dilated, stressing the role of lymphatics and possibly of excessive skin trauma and friction in the development of bullous lesions.