Concomitant extraspinal hyperostosis and osteoporosis in a patient with congenital ichthyosis.

Ichthyosiform dermatosis is a term referred to a group of disorders that have as their basis a disorder of keratinization (1). These conditions which are present at birth result in a generalized dry, scaly skin without any inflammation. There are several types of ichthyosis based on their clinical presentation and mode of inheritance. The most common types are: ichthyosis vulgaris, X-linked recessive ichthyosis, epidermolytic hyperkeratosis (bullous), lamellar ichthyosis and non-bullous ichthyosiform erythroderma. Lamellar ichthyosis, which is inherited in an autosomal recessive pattern, shows genetic heterogeneity with the most severe type being due to mutations in the transglutaminase-1 gene. This condition presents with skin changes at birth and cases are referred to as collodion babies. Initially, the stratum corneum is smooth and appears as though it is covered with cellophane. This layer is discarded a few days after birth, leaving a generalized inflamed and scaly appearance. The skin is tight at this stage and may cause ectropion, and difficulties in feeding and temperature regulation. Lamellar ichthyosis is characterized by plate-like scales that last for life and can significantly impact the patient's quality of life (2). We report here a case of multiple extraspinal hyperostoses concomitant with marked osteoporosis and vitamin D deficiency in a patient taking acitretin for 20 years due to severe congenital lamellar ichthyosis.