Thanks for posting your query at DoctorSpring.com. I can understand your concern.
This seems to be a bacterial infection, as I can see a pus filled lesion with lots of redness on the ear around it.
I would recommend a course of oral antibiotics for him. An antibiotic like erythromycin would be helpful. Also application of mupirocin cream twice a day for two weeks would help resolve the lesion.
It would be important to give him a course of oral antibiotics, or else there would be swelling in the surrounding area and a lot of pain too.
Please let me know if you have any queries.