P080 Acroosteolysis: a rare complication or a co-occurrence with Juvenile Idiopathic Arthritis?

Abstract Background Acroosteolysis refers to a destructive process involving the distal phalanges of the fingers and toes that may extend to metacarpals or metatarsals. Rarely idiopathic, the diagnosis of primary acroosteolysis requires ruling out other causes. Juvenile idiopathic arthritis is an exceptional aetiology of acroosteolysis occurring mainly in psoriatic arthritis. Here by a case of juvenile idiopathic arthritis associated with acroosteolysis of the toes. Methods A 13-year-old girl with no past medical history, presented to our department of rheumatology with oligoarthritis affecting both wrists and knees. She had no familiar history of psoriasis nor rheumatic diseases. She described a dull ache and recurring swelling of knees evolving for >6 years associated with a macular rash of the chest without fever. On examination, the knees were swollen with a limited range of motion of < 90°. Examination of the spine and sacroiliac joints was unremarkable. There was no deformity, no dysmorphic syndrome nor ligamentous hyper laxity. The mucocutaneous examination was normal. Similarly, there was no hepatosplenomegaly or swollen lymph nodes. Laboratory investigations showed high acute phase reactants and normal blood count. Rheumatoid factor, anti-cyclic citrullinated peptide antibodies and antinuclear antibodies were also negative. Besides, she was negative for HLAB-27. Ophthalmic examination did not show any sequelae of uveitis. Results Plain radiograph of the feet revealed bone resorption of the second and fifth distal phalanges without signs of reconstruction. Other secondary causes of acroosteolysis were ruled out. The diagnosis of oligoarticular juvenile idiopathic arthritis was made. In view of the involvement of the distal phalanges, the phenotype of psoriatic arthritis was probable. The patient was initially treated with non-steroidal anti-inflammatory drugs as well as intraarticular injections of corticosteroids in knees. As the flares persisted, she was put on Methotrexate at a dosage of 15 mg per week with marked clinical improvement. Conclusion Our case illustrates a possible occurrence of acroosteolysis of the feet in the field of an active juvenile idiopathic arthritis. It is important to rule out other causes and make a rapid diagnosis in order to ensure appropriate management decisions.