Sarcoidosis and spondyloarthritis: A coincidence or common etiopathogenesis?

Background Sarcoidosis is a multisystem granulomatous disease. Co-existence with spondyloarthritis (SA) has been more described as an adverse effect of anti-TNF α therapy than an association. We report herein a case of a typical sarcoidosis confirmed by histological proofs and an advanced SA with a bamboo column. Case Presentation A 48-years-old woman presented with inflammatory back pain for 5 years and ankle swelling for 1 year. On physical examination, she had an exaggerated dorsal kyphosis and disappearance of lumbar lordosis with limitation in motion of the cervical and lumbar spine. Laboratory tests did not show an inflammatory syndrome or hypercalcemia. Plain radiographies of the spine and pelvic revealed a triple ray appearance with sacroiliitis grade 4. Chest radiography and CT confirmed the presence of bilateral hilar lymph nodes and parenchymal nodes. Bronchoscopy and biopsies were performed showing non-calcified granulomatous reaction without cell necrosis. The diagnosis of SA was performed based on 9 points of Amor criteria associated with pulmonary sarcoidosis. She was treated with 15 mg per week of methotrexate and 1mg/kg/day of prednisone for pulmonary disease with good outcomes. Conclusions Sarcoidosis may be associated to SA besides paradoxical drug effect. The same physio pathological pathways mediate by TNF α are arguments for association than hazardous coincidence.