pre school DTaP/IPV/Hib vaccine - swollen hot red arm

[minimenace]

My 3.5 yrs old DS had his pre school DTaP/IPV/Hib vaccine on Friday.

Yesterday (Saturday) he had a fever and his arm was swollen he wasn't happy - gave him calpol and he slept quite a bit.

Today his arm has swollen even more and is red hot to touch. The swelling and redness has spread from the site of the vaccine all the way down to his elbow and his skin looks shiny. There is a whitish lump about the size of a biscuit below the site. He is still wiped out asleep on sofa all afternoon.

I know the leaflet lists as a side effect :

very common (in more than one in 10 children) Pain and swelling in the area where vaccine was injected, tiredness.
Common (in less than 1 in 10, but more than 1 in 100 children) redness and itching in the area where the vaccine was injected, fever .... etc etc

How do I know if what he has in a normal reaction as listed or something else like an infection. surely it shouldn't be spreading ?

When should I be worried / take him back to doc to get checked ?

please help ?

About 2 weeks ago my dd had a very hot, tight red area around the injection site about 48 hrs afterwards too. Probably about 10 cm sq around it. She didn't have a fever or complain about it though.

I looked on the NHS website and found this info:

www.nhs.uk/Conditions/DTaP-IPV-booster/Pages/Side-effects.aspx

www.mhra.gov.uk/home/groups/pl-a/documents/websiteresources/con2023022.pdf

The second doc outlines that hotness and swelling is a common side effect. This did reassure me and as it was a saturday /sunday when it happened (following jabs on friday) I decided to leave it and see how it went. By Monday it had calmed right down.

If you are worried though give NHS direct a call.

Thank you that second link is very helpful and explains it in detail. although it says you should look for any other signs it could be an infection ... like what ? normally a fever which he has anyway it's another side effect.

just so difficult to tell - however I am reassured a little at the size of it now having read that.

Still the same not worse but no better, although fever is lower this morning and he has insisted on going to preschool.

I'm going to see how he is at lunchtime and call the nurse then. in mean time if anyone has any ideas ?
I feel silly worrying when it's a 'common' side affect.

How is your DS?