Thank you for your query.
Application of Bacitracin
behind the ear for slits is not the correct approach. I suggest that you ensure that the area is dry and apply some bland ointment or just vaseline two to three times a day.
If the piercing of the ear for ear rings has caused an infection at the site then it needs to assessed and antibiotics be given for it. If the swelling does not heal then the ring or thread which has been used will have to be removed, the wound left to heal and then again do a piercing after 6-8 weeks of the healing of the wound.
I hope I have answered your query to your satisfaction.
Wishing your daughter an early recovery.
Rajiv K Khandelwal