Review Question - QID 107241

This patient is suffering from non-bullous impetigo, a gram-positive bacterial skin infection. The optimal treatment for non-bullous impetigo of the nares is topical mupirocin.

Impetigo is a bacterial skin infection, most typically caused by Staphylococcus aureus or Streptococcus pyogenes (i.e., group A ß-hemolytic streptococcus). Presentation is characterized by ulcers or erosions with honey-colored crusting on the face and extremities with a predilection for areas of previous skin trauma (i.e. insect bites, eczema, or herpetic lesion). There are two types of impetigo: nonbullous (70%) and bullous (30%). Both types typically resolve within 2 to 3 weeks without significant scarring.

Hartman-Adams et al. review the diagnosis and management of impetigo. Impetigo is the most common bacterial skin infection in children aged 2-5. The preferred treatment for nonbullous impetigo includes topical antibiotics such as mupirocin, retapamulin, and fusidic acid. However, oral antibiotics can used in bullous impetigo with large bullae. Amoxicillin/clavulanate, dicloxacillin, cephalexin, clindamycin, doxycycline, minocycline, trimethoprim/sulfamethoxazole, and macrolides are all options in such instances, but penicillin is not.

Bangert et al. discuss the challenges of impetigo treatment in the era of increasing antibiotic resistance, particularly methicillin-resistant staph aureus (MRSA). Resistance rates to common topical therapies such as mupirocin and sodium fusidate are increasing and have been reported to range from 5% to 50%. To decrease resistance, they suggest using topical disinfectants, such as sodium hypochlorite (bleach) baths, as adjuvant therapy in populations with recurrent Staphylococcal infections. They also stress the importance of using culture sensitivities to determine appropriate antibiotic selection.

Figure A shows a case of nonbullous impetigo. Note the honey, golden-colored crusting erosions around his nares. Illustration A displays a case of bullous impetigo. Note the scattered flaccid and fluid-filled blisters over a patient's right buttock.

Incorrect Answers:
Answer 1: Topical hydrocortisone 0.1% may be effective for treatment of atopic dermatitis (eczema) flares. However, it will not treat bacterial superinfection of eczema lesions.
Answer 3, 5: Oral trimethoprim-sulfamethoxazole or oral dicloxacillin are good options for the treatment of complicated impetigo or extensive bullous impetigo. Topical therapy is more appropriate and effective for treating localized infection.
Answer 4: Due to extensive resistance patterns, penicillin should not be used for the treatment of impetigo.