Acute Exacerbation of Ankylosing Spondylitis After an Iron Dextran Infusion

An acute exacerbation of spondylitis developed after an intravenous infusion of iron dextran in a 49-year-old patient with known ankylosing spondylitis. The acute inflammatory reaction seems analogous to that observed recently in rheumatoid arthritis. Underlying arthritis of a nonspecific nature may be a necessary requirement for the iron-induced reaction (which may be owing to the effect of iron on pyrophosphatase) to occur.