Reactions to total dose infusion of iron dextran in rheumatoid arthritis.

Ten patients with active rheumatoid arthritis were given a total dose infusion of iron dextran for anaemia. One had an immediate anaphylactoid reaction; the other nine had a brief exacerbation of arthralgia and joint dysfunction of up to seven days' duration. The erythrocyte sedimentation rate rose by an average of 23 mm. in one hour (Westergren), but this often took longer than seven days to settle to the preinfusion level.It is suggested that this response is probably not due to an exacerbation of rheumatoid arthritis but to a delayed hypersensitivity reaction to the dextran portion of the iron dextran complex. This treatment is potentially dangerous in rheumatoid arthritis; we recommend a preliminary test dose and that the infusion be started very slowly under supervision.