Thanks for the query.
you have bronchial problem, that means you are prone to develop allergy
the wheals are due to allergic reaction
which may be caused by the antibiotic
Dont worry take anti histamine
as adviced by your doctor
You will be fine.
Please meet a dermatologist
if it persists.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.