Arthritis and osteonecrosis in a patient with thrombophilia

This case report describes a very rare entity of thrombophilia manifesting as persistent arthritis and digital ulcers. A 9-year-old Egyptian girl pres ented with a 2-year history of persistent arthritis and digital ulcers. The case was followed up after 4 years. The clinical manifestations and labora tory investigations are recorded. Thrombophilia with partial protein C defi ciency appeared to be responsible for the clinical manifestations with unde rlying ipsilateral osteonecrosis of patella and calcaneum and resorption of the terminal phalanges. Her older sister showed the same picture with addi tional pulmonary hypertension. In conclusion, arthritis and osteonecrosis a ppear as a rare presentation of thrombophilia and protein C deficiency, and ignorance of this may lead to misdiagnosis or confusion with other childho od rheumatic diseases.