Brief Answer:
Could be a small haematoma.

Detailed Answer:
Hello,

Thanks for writing to us.

It would have been better if you would have attached a photograph of the blister. Any way Vacade an anticancer drug used to treat multiple myeloma. It decreases platelet counts so patients on Valcade are prone to bleeding from minor abrasions or from injection pricks. What you husband most probably has developed is a small haematoma (collection of blood under skin).It may be having a super added infection over it. You can apply over it heparin ointment (available in market by the name of thromophob and lioten gel), which will help in dissolving small haematoma. In case of infection, antiseptic ointment can be applied. Examination by a treating physician is advisable, to rule out infection at injection site or too much decrease in platelet.

Hope this answers your question.

If you have any more queries write me back I am readily available to answers your queries.
Regards,
Dr Sadiq

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