Allergies are common in children and it can be due to contact, inhalation or ingestion of a triggering substance. Allergies are likely to occur in children if there is a maternal history of asthma
. Also there are lot of food triggers that can result in allergies. These allergies can manifest in any manner like rashes over the face as you mentioned.
If it is a recurring problem it is likely to be allergic. It is not easy to ascertain the exact allergen but certain tests are available which help in spotting the trigger.
Kindly consult your skin specialist for the problem. In the meantime continue the antibiotic for at least 7 to 10 days. Momate is indicated for dermatitis. You can also take an anti allergic like syrup allegra
to give you better results.