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 presented with a 2-year history of persistent arthritis and digital ulcers. The case was followed up after 4 years. The clinical manifestations and laboratory investigations are recorded. Thrombophilia with partial protein C deficiency appeared to be responsible for the clinical manifestations with underlying ipsilateral osteonecrosis of patella and calcaneum and resorption of the terminal phalanges. Her older sister showed the same picture with additional pulmonary hypertension. In conclusion, arthritis and osteonecrosis appear as a rare presentation of thrombophilia and protein C deficiency, and ignorance of this may lead to misdiagnosis or confusion with other childhood rheumatic diseases.