thanks for your query.
your baby is having ear infection
,rashes can be because of drug allergy
or viral infection.
postauricular lymph adenopathy is seen in case of ear infection and will subside in few days.
For hives i suggest you to apply calamine lotion 3 to 4 times a day and give some antiallergic like benadryl
in prescribed dosage.In case symptoms do not improve take her to pediatrician
Your child will be fine.