Whipple's disease with normal duodenal histology and ankylosing spondylitis

History and admission findings: A 33-year-old woman with increasing back pain was referred to our hospital 8 years ago. As she had ankylosing sacroilitis and peripheral arthritis she was diagnosed as having ankolysing spondylitis with involvement of the peripheral joints. She recently developed persistent diarrhea, abdominal symptoms and weight loss. Investigations: Laboratory findings revealed a chronic inflammatory disease. Infection of the gastrointestinal tract was excluded. Duodenal biopsy was normal on PAS staining, Tropheryma whipplei-DNA was detected by the polymerase chain reaction (PCR). Treatment and course: Initially the patient was treated for 6 months with diclofenac and ibuprofen without improvement of her condition. As the spondylitis persisted, she was given anti-TNF-alpha treatment 7 years after the onset of symptoms. When Whipple's disease was diagnosed this treatment was stopped and antibiotics (ceftriaxone) was started and then continued with co-trimoxazole for one year with significantly improvent in her condition. Conclusions: In patients presenting with symptoms involving several organs, rare systemic diseases should be considered. if symptoms are typical of Whipple's disease, but duodenal biopsies are negative on PAS staining, a sensitive PCR assay may detect T. whipplei-DNA confirming this infection. Appropriate antibiotic treatment can then be initiated.