Surely an allergy would come up quicker than that...?

[kawazuki]

possibly could be a mix of both.

this may sound weird but in my time as a nurse i have found many people allergic to grass things are also sensitive to penicilline.

i myself am allergic to grass ( paspalam) and penicillinand a doctor once told my mum they were linked.

a good wash with a ph balanced soap will help if he is itchy at all

[Marlene]

The rash could actually be a residual part of the virus he had and may not be an allergy at all. It's not uncommon for a viral rash to appear after other symptoms have gone (or it could be a whole new virus)...but it would be a bit strange for an allergy to come out that long after the antibiotics are finished.

[Liz]

Yeah I was thinking along the lines of the rash being related to the virus. Why was he on antibiotics for a viral cold? *confused*