The correct answer is:

Start oral clindamycin, discharge with close outpatient follow-up

Educational Objective:

Distinguish, diagnose, and treat bullous impetigo (staphylococcal pustulosis).

Key Point:

While the patient is not systemically ill, the lesions are widespread enough to warrant oral antibiotic therapy.

Explanation:

The patient has bullous impetigo (staphylococcal pustulosis) and is not systemically ill.

Mild localized infection may be treated with topical antibiotics such as mupirocin, while more widespread lesions (as in this case) should be treated with an oral anti-staphylococcal medication.

Afebrile and otherwise well-appearing infants do not require a full sepsis work-up and admission for IV antibiotics.

However, if IV antibiotics were to be used to treat this patient, better MRSA coverage, rather than ampicillin and cefotaxime, would be indicated.

Oral antimicrobial therapy with trimethoprim-sulfamethoxazole (TMP-SMX), clindamycin or doxycycline is recommended for afebrile and otherwise healthy patients with suspected staphylococcal skin infections.

However, TMP-SMX is to be avoided in infants < 2 months of age, and doxycycline should be avoided, if possible, in those < 7 years of age.

Oral clindamycin is the best choice of those listed.

References:

Van Praag et al, Pustular Disorders in the Neonate, Pediatric Dermatology 1997 vol 14(2):131-143.

Fortunov RM et al, Evaluation and Treatment of Community Acquired Staphylococcal aureus Infections in Term and Late-Preterm previously healthy Neonates. Pediatrics 2007 120(5): 937-945.

Red Book 2015, 29th edition, Committee on Infectious Disease, American Academy of Pediatrics; pp 653-668.