[Generalized ichthyosis associated with a spastic syndrome of the lower limbs, a variant of Sjögren-Larsson syndrome? Light and electron microscopy study of ichthyosis and its evolution with oral etretinate treatment].

A generalized ichthyosis with an associated spastic syndrome of the lower extremities, clinically suggestive of Sjögren-Larsson syndrome, was observed in a Tunisian boy. The fatty acid analysis of the serum phospholipids revealed significant abnormalities in the fatty acid pattern of phospholipids. However, the alterations observed were different from those reported in Sjögren-Larsson syndrome. We report light and electron microscopic changes in the ichthyotic skin of this patient, which have not been previously reported in lamellar ichthyosis and in Sjögren-Larsson syndrome. The epidermis was moderately hyperplastic and covered with a thick, compact, orthokeratotic stratum corneum. The stratum spinosum was strikingly altered in some areas. Varying numbers of keratinocytes contained big vacuoles, measuring often up to the size of the nuclei; the vacuoles, were well limited but only partially lined by a membrane, they were empty or contained small amounts of a flaky material. Attempts to stain the vacuoles with PAS, Alcian blue and Fettrot were negative. Etretinate treatment produced a marked shedding of the horny layer without significant improvement of the clinical appearance. The described microscopical alterations of the epidermis remained mostly unchanged during treatment, but, in addition, a marked oedema and vacuolisation of the upper stratum granulosum was observed.