Thanks for your query.
I will try my best to provide you with best possible professional recommendations to your questions.
Putting a small pin hole in the ear drum has been used to relieve pressure before. If the pressure is not relieved, the ear drum can burst to prevent that either hole or the tubes are inserted in the ear drum.
It is tried when the infection is not controlled by the medications like antibiotic oral or by ear drops. Usually antibiotics are given after piercing the ear drug. Pierced ear drum heal without any deformity
I advice you to take care that water does not enter the ear while giving bath to your son, the ear should be kept dry.
Yet again, I do hope that you have found something helpful and I will be glad to answer any further query.