Microsoft Word - DRM257BF

A. Tostia, U. Albisinni, V. Bettoli, L. Merlini, L. Lama, Departments of Dermatology, Neuropathology, and Radiology University of Bologna, Bologna (Italy) Dear Sir, The recent article by Gilbert et al. [1] regarding the lack of skeletal radiographic changes during short-term etretinate therapy for psoriasis prompt us to report a peculiar skeletal involvement that we have observed in 2 patients treated with etretinate for keratini-zation disorders. Case Reports Case 1 After 2 years of treatment with etretinate for lamellar ichthyosis a 22-year-old man was submitted to an X-ray screening examination of the spinal cord which revealed the presence of a segmental ossification of the posterior longitudinal ligament (OPLL) at the L4-L5 levels. No symptoms referable to spinal cord compression were present and a detailed neurologic examination was negative. The cumulative dose of etretinate received by this patient was about 35 g. Case 2 A 65-year-old woman affected by severe pustular psoriasis had been treated during the last 2 years with several courses of etretinate, 1 mg/kg, daily (the total cumulative dose of the drug was about 15 g). Since the patient complained of severe neck pain we obtained an X-ray examination of the spinal cord which disclosed a localized OPLL at the C6 level. The neurological examination revealed only stiffness of the cervical spine. Discussion Skeletal abnormalities are probably the major concern in long-term therapies with retinoids [2, 3]. Among the various radiographic changes described in patients treated with retinoids, the ossification of the posterior longitudinal ligament is certainly the most important as it can result in spinal cord compression. In fact since the posterior longitudinal ligament is located inside the spinal canal, the ossification of this ligament can cause a progressive compression of the spinal cord. An OPLL has been recently described in 2 patients after a long-term treatment with isotretinoin for severe ichthyosis [4].