Retinoid‐induced skeletal hyperostosis in disorders of keratinization

For disorders of keratinization, topical treatment alone may be ineffective, and systemic retinoid therapy may be indicated. Treatment with systemic retinoids (acitretin, isotretinoin and alitretinoin) has been shown to be effective in reducing disease severity; however, potentially rare adverse effects (AEs) may occur, including hyperostotic skeletal changes. The true prevalence of this AE in adult patients administered life‐long therapy is unknown. We identified 3 of 127 (2.4%) patients (with ichthyosis or Darier disease) who had been prescribed isotretinoin with or without acitretin, and who developed radiological signs and clinical symptoms of hyperostosis and ligamentous ossification. This clinical review highlights the significance of retinoid‐induced skeletal hyperostosis in patients prescribed long‐term, high‐dose retinoid therapy for disorders of keratinization. Patients commencing systemic retinoid therapy, particularly women of childbearing age, should be counselled about this important and potentially serious AE, especially if long‐term treatment is indicated.