What insulin are you using ?
What have you eaten ? Shellfish ? Nuts ?
Check your blood sugars if high ?
If you are using Levemir insulin - it can cause red itchy site areas .
Preservatives in the insulin can cause this reaction with 'some' persons .
Did this with me (my first attempts with it)
I recently had shingles with raised BG for couple of weeks with them .
They were all over my body following my nervous system .
Visually red raised swollen spots grouped up together and VERY painful too .
These can take weeks/months to go - as I am finding out
If you are in pain or having any breathing problem - I suggest to seek a doctors advice .