Engelmann's disease of bone--a systemic disorder?

A patient with Engelmann's disease of bone (progressive diaphyseal dysplasia) also suffered from Raynaud's phenomenon, multiple nail fold infarcts, anaemia, leucopenia, hepatosplenomegaly, and a raised erythrocyte sedimentation rate. Her mother, who also had this inherited bone disease, was known to have Raynaud's phenomenon, necrotising vasculitis, and digital gangrene. Review of other published cases of Engelmann's disease indicates that some of these features are not uncommon. It is argued that Engelmann's disease is not primarily a metabolic bone disease but may be a systemic disorder which might be included within the spectrum of the inflammatory connective tissue diseases. The beneficial effects of steroid treatment on both skeletal and systemic features are compatible with this view.