A 10-year-old girl is brought to the emergency department for evaluation of a bite wound. Last night, the girl had a fight with her 12-year-old stepbrother, who bit her on the forearm. This morning, the girl's arm "looks worse." The stepbrother is HIV-positive and acquired it from his mother at birth. He takes antiretroviral therapy; his most recent CD4 count was 1100 cells/µL, and his HIV viral load was undetectable. The patient has no known medical problems, and takes no medications. Her vital signs are normal. Examination shows 2 deep puncture wounds on the left forearm. There is warmth, erythema, and swelling around the bite marks. The skin is mildly tender to palpation. No fluctuance is palpated. The wound is irrigated thoroughly with saline and local wound care is provided. Which of the following is the most appropriate next step in management of this patient?

Question

A 10-year-old girl is brought to the emergency department for evaluation of a bite wound.  Last night, the girl had a fight with her 12-year-old stepbrother, who bit her on the forearm.  This morning, the girl's arm "looks worse."  The stepbrother is HIV-positive and acquired it from his mother at birth.  He takes antiretroviral therapy; his most recent CD4 count was 1100 cells/µL, and his HIV viral load was undetectable.  The patient has no known medical problems, and takes no medications.  Her vital signs are normal.  Examination shows 2 deep puncture wounds on the left forearm.  There is warmth, erythema, and swelling around the bite marks.  The skin is mildly tender to palpation.  No fluctuance is palpated. The wound is irrigated thoroughly with saline and local wound care is provided.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

Explanation: This patient has early signs of soft-tissue infection around the bite wound, including warmth, swelling, and tenderness to palpation. Most soft-tissue infections from human bites are polymicrobial, with a mixture of anaerobic and aerobic organisms. Treatment must include anaerobic coverage, particularly against Eikenella corrodens. Oral amoxicillin/clavulanate (or ampicillin-sulbactam if intravenous therapy is indicated) is the drug of choice for such infections as it covers all of the common pathogens in human bite infections. (Choices B and C) Cephalexin is effective against Streptococcus viridans and methicillin-sensitive Staphylococcus aureus.Clindamycin has activity against staphylococci and viridans group streptococci. Neither cephalexin nor clindamycin provides coverage against E corrodens and therefore is not appropriate as monotherapy for infections due to human bites. (Choice D) Observation alone is not appropriate for this patient. She has signs of developing cellulitis and requires treatment. (Choice E) Contact with saliva is an extremely rare cause of HIV transmission. Bite wounds are generally considered low-risk exposures unless the biter has oral bleeding at the time of the bite. The absence of a detectable viral load in the stepbrother further decreases the transmission risk in this patient, and post-exposure prophylaxis with antiretrovirals is not recommended. Educational objective: Amoxicillin/clavulanate (or ampicillin-sulbactam if parenteral therapy is needed) is the drug of choice for significant wound infections due to mammalian bites, including human bites. It provides coverage against oral aerobic and anaerobic flora, including Eikenella corrodens. References: Animal bite-associated infections: microbiology and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/21342069) Human bites: bloodborne pathogen risk and postexposure follow-up algorithm. (http://www.ncbi.nlm.nih.gov/pubmed/23862301)

A 10-Year-Old Girl Is Brought to the Emergency Department for Evaluation