Clinical follow-up with no additional treatment is indicated at this time for this patient who has undergone incision and drainage of a furuncle (boil). Usually, incision and drainage alone is the primary treatment recommended for a patient with a simple furuncle. Antibiotics generally are recommended only when the response to incision and drainage is inadequate, when involved areas are challenging to drain (such as the genitalia, hands, or face); when disease is extensive or rapidly progressive with associated cellulitis; in immunodeficiency and other comorbidities; for very young or very old patients; those with clinical signs of systemic illness; and in the presence of associated septic phlebitis. Furuncles are typically due to community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Empiric use of adjunctive antibiotics with CA-MRSA activity after incision and drainage of a furuncle is generally reserved for patients who are immunosuppressed, who do not respond adequately to incision and drainage or antibiotics without MRSA activity, or who have systemic signs of infection.

Oral dicloxacillin has activity against methicillin-sensitive S. aureus (MSSA), but not MRSA. It would be recommended for adjunctive use when culture of purulent material from a furuncle demonstrates MSSA.

Because of the high likelihood that MRSA may be the causative agent, when antibiotics are used, empiric treatment with agents with activity against MRSA is recommended. Doxycycline has activity against MRSA and would be a reasonable choice, but it is not indicated for this patient who has undergone incision and drainage of his furuncle. Trimethoprim-sulfamethoxazole is another reasonable option for empiric MRSA therapy if antibiotic therapy is needed, although this agent would be contraindicated in this patient with a known allergy to this medication.

Although it is bactericidal against some strains of MRSA, rifampin monotherapy is not recommended because of the development of resistance.