Coexistence of ankylosing spondylitis and rheumatoid arthritis in a female patient.

Ankylosing spondylitis (AS) and rheumatoid arthritis (RA) are two distinguished representatives of inflammatory rheumatic diseases. The two diseases differ significantly in their etiology, pathology, clinical signs, and in the nature of articular manifestations. Their association has been a rarity in the literature. Here, authors describe a case of a 55-year-old female patient with AS associated with RA. Her spinal symptoms started in 1979, and the diagnosis of AS was established based on the typical clinical picture and X-ray. She developed severe spinal deformity during the next decades. In 2005, peripheral polyarthritis developed, although neither the diagnosis nor the treatment was modified. In 2007, authors diagnosed seropositive RA. Therapy included anti-inflammatory therapy and traditional disease-modifying agents, eventually followed by biological therapy.