Do you mind if I ask what the plastic is for? I am yet to start Chemo in 2 weeks so radiation is way away but wondering as I am allergic to plastic so thinking this is going to be an issue and wondering how to get arround it....
As far as itchiness goes any antihistamine you can get at the chemist (like telfast, claratine and such will help). Over the counter creams for insect bits help a great deal but you need to be able to to the spot in question....
Sometjing you can use even if you cannot get to the skin is ice. I suffer from severe allergies and get skin breakouts (those horrid white blisters all the time) and the fastest way to get relief is ice. If the area is small just an ice vube or if karge a bag of frizen veg like peas or corn is fabulous as it will mould to your shape. Relief is instant and helps it not spread.
If you find it too hard to bear the cold place a kitchen towel arround the frozen item. Or wet a kitchen towel leave in freezer 5 to 10 min as then it is very cold but not as cold as ice and use that on the affected area to get relief....