The term recall reaction
refers to erythema (redness of the skin) in areas of previously quiescent sunburn or radiotherapy. The exposure to the sun or radiotherapy may have been weeks to months ago and the skin may have fully recovered until the patient was given chemotherapy.
The actual mechanism is not fully understood but it has been postulated to occur as a result of the recovering keratinocytes (skin cells) being damaged by the chemotherapy drugs, as these cells are the ones which are most rapidly dividing and regenerating.
The most common drugs which can cause this are:
Gemcitabine
Methotrexate
Docetaxel
Etoposide
Doxorubicin
Treatment involves minimising exposure to the sun, good wound care. There is possibly a role for topical steroid creams to reduce the inflammation.