Myositis due to chemotherapy

hello,

I was wondering whether anyone has ever treated a patient for myositis secondary to having chemotherapy. I have currently been referred a patient who is having chemotherapy and who has developed myositis in his legs as a result. He initially developed myositis in his quads after his first bout of chemo - this resolved but he now has it in his gastrocemius' after his second bout of chemo. The medical team have decided to lay off the chemotherapy to give the patient a chance to recover fully from the myositis - and I was just wondering if anyone had seen a patient with a similar experience. Essentially, I am just concerned that I am treating him during an acute flare up and I am not sure whether I should wait to see if it starts to resolve and then give stretching and strengthening exercises - or does anyone think that it is ok to give some stretching exercises at present and then to progress with strengthening once his condition starts to resolve?
Many thanks to anyone who may be able to share any advice.

Emily

hi emily,

with respect to your query regarding physio therapeutic management, I have nothing much to offer apart from symptomatic treatment approach.

on the other hand just thought of sharing the "radiation recall phenomenon" one of the most common cause of myositis and associated complications following chemotherapy.

well when patients are exposed to certain chemotherapy agents, a few weeks or months after completion of radiation treatment, some acute radiation reactions may re-occur. this phenomenon was first described by dr. D'Angio, university of pennsylvania, not sure about the year:).

some of the chemotherapy agents that have been reported to cause radiation recall reactions include doxorubicin (adriamycin), dactinomycin, paclitaxel (taxol), and methotrexate.

in addition to myositis, skin reactions, gastrointestinal and urinary reactions as well as radiation pneumonitis have been reported in association with this phenomenon. the exact pathogenesis for radiation recall phenomenon remains unclear.

some investigators have suggested that it may be the result of vascular damage, epithelial stem cell sensitivity, or drug hypersensitivity. one proposed mechanism suggests a lowering of the inflammatory threshold in radiated tissue, which leads to a non-immune inflammatory reaction upon exposure to certain drugs.

hope it throws some light onto your post/issue.

cheers,

thomas

Hi Thomas,

thank you so much for your reply - it has been very helpful and has certainly given a better insight into how to go about treating it.

many thanks

Emily