My father is 88 years old and a week ago he started getting red patches with bumps filled with puss and they are also coming out all over his neck. He said they are painful. Can you please enlighten me as to what it might be.
Thank you.

I don't know that his age matters - are they cysts? Boils?

Boils (Skin Abscesses) Information, Causes, Symptoms, Treatment and Prevention by MedicineNet.com

Perhaps he has Shingles? http://www.patient.co.uk/health/Shingles.htm
Another link: http://www.emedicinehealth.com/shingles/article_em.htm