Thanks for your question on Healthcare Magic.
I can understand your concern.
Yes, fluid aspiration from neck
abscess is must for the diagnosis of type of infection.
Since you are diabetic, this kind of purulent infection can be seen with mixed infection like aerobic, anaerobic bacteria with
tuberculosis.
So abscess fluid (pus) culture and sensitivity report is needed.
Culture will isolate the causative organism and sensitivity report will guide about effective antibiotic treatment.
For this we need abscess material and it is available only after aspiration. It is not much painful procedure. Intensity of pain will be similar to simple needle prick. If you really afraid of pain then ask your use local
anesthetic agent (lignocaine) before the procedure.
Don't worry, this won't cause pain.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.