O. Kaloudi1, F. Bandinelli1, S. Guiducci1, M. Matucci Cerinic1
1Department of Medicine and Surgery, Division of Rheumatology, University of Florence, Florence, Italy
Rare diseases are serious chronic diseases, and often life-threatening affecting a small number of people compared to the general population. People affected by rare diseases are more vulnerable from a psychological, social, economical and cultural standpoint for the lack of sufficient scientific and medical knowledge. Camurati-Engelmann (CE) disease, Pachydermoperiostosis (PDP) and Stiff Skin Syndrome (SSS) are rare diseases of rheumatological interest.
CE is characterized by cortical thickening of the diaphysis of tubular bones, leading to increased diameter of the bone and narrowing of the medullary cavity. The disease is autosomal dominant transmitted, due to an overexpression of TGF-beta 1. The symptoms are waddling gait, diffuse and disabling bone pain, muscular weakness, and easy fatigue. The radiological picture is diffuse and symmetric cortical thickening and sclerosis of the diaphysis of tubular bones, with sparing of the epiphysis. The targets of treatment are pain control and modification of disease evolution. Administration of analgesics and/or NSAIDs usually achieves no efficient response. Pain relief is obtained with corticosteroids.
PDP is dominant autosomal trasmitted disease that involves several organs and systems: skin (seborrhoea pachydermia, cutis verticis gyrata), bones (periostosis, acroosteolysis), joints (arthritis or arthralgia) and acral soft connective tissues (finger clubbing). Two hypothesis have been proposed: the first concerns the role of PDGF producted by platelets not deleted by pulmonary circulatory and the second suggests that peripheric endothelial damage may stimulate the synthesis of PDGF by platelets. Radiologic examination reveals irregular periosteal proliferation with cortical thickening of the long bones, metatarsal and metacarpal bones, and phalanges. The scintigraphy is useful for early diagnosis. NSAIDs may improve joint sympthoms with not efficient response. Colchicine is the gold standard for arthritis, improving joint symptoms and effusion.
SSS is clinically characterised by skin stone-hard areas leading to a limitation of joint mobility. Until now, about 20 SSS patients have been described in the literature, with few familiar cases. The disease progresses over time until the skin of whole body becomes fibrotic with subsequent growth retardation and joint contractures. In recent observations, the most relevant lesions were localized in the muscularis fascia, which was thickened by a hyalinized collagenous tissue. No therapy is known and physical therapy is the only treatment.
Knowledge of the natural history of rare diseases may be improved by decreation of registers. New hopes arise from european networking between centres and from research on orphan drugs use.