A rare case of sarcoid osteitis in a child with response to methotrexate

Sarcoidosis is a disease of unknown origin characterised by noncaseating granuloma and can involve any tissue or organ. Osseous involvement in sarcoidosis is rare in children and long tubular bone involvement is even rarer. We present a case histologically proven as sarcoid osteitis of radius and humerus that had a dramatic response to methotrexate.

A 9 year old Jamaican boy with known sarcoidosis, diagnosed in Kingston by cervical lymph node biopsy initially presented to us with high grade pyrexia, peripheral lymphadenopathy and painful shiny swelling in both shin. Tentative diagnosis made was sarcoid related osteitis. X-ray of legs (Figure 1) showed periosteal reaction in leg bones. He was treated with subcutaneous methotrexate.

Figure 1

X-ray of legs showing periosteal reaction in leg bones.

After 3 years of drug-induced remission, methotrexate was stopped. Eight months after stopping methotrexate he presented with painful swelling of left arm and forearm. Radiograph showed circumferential lesion with periosteal reaction and MRI scan confirmed surrounding oedema suggestive of acute lesion. Sarcoid osteitis was confirmed on biopsy by the presence of characteristic non caseating granuloma with giant cells. He was restarted on methotrexate upon which the lesions resolved in a few weeks.

Authors conclude that long bone involvement in a child with sarcoidosis is rare but we should have low threshold for biopsy in known case of sarcoidosis presenting with radiological feature of osteitis to confirm the diagnosis and for treatment. In our case there was excellent response to methotrexate.