An otherwise healthy 38-year-old man reports six days of a painful boil on his upper back. Vital signs are BP 128/82, HR 70, RR 16, T 98.6 F. He has been applying warm compresses to the area, but it is increasing in size, and the pain is worsening. On exam, you palpate a 1 x 1 cm erythematous, tender, fluctuant abscess without induration or surrounding cellulitis. What is the most appropriate treatment for your patients abscess?