Staphylococcus aureus antibiotic susceptibility patterns in pediatric atopic dermatitis

Abstract

Background/objectives: Staphylococcus aureus is the most prevalent bacterial pathogen in atopic dermatitis (AD) patients presenting with skin infections. Despite the known association between S aureus and AD, guidance on empiric antibiotics for skin infections in pediatric AD patients is limited.

Methods: We conducted a retrospective study over a five-year period to characterize the S aureus strains recovered from pediatric AD patients with clinically apparent bacterial skin infections treated in an academic medical center. We assessed patient demographics and dilute bleach bath usage to determine whether these factors were correlated with methicillin resistance. Culture results from our AD cohort were also compared to those from pediatric patients presenting to the Saint Louis Children's Hospital emergency department (ED) with S aureus skin abscesses from 2013 to 2015.

Results: Methicillin-sensitive S aureus (MSSA) was more prevalent (77.8%) than methicillin-resistant S aureus (MRSA) (22.2%). There was no correlation between MRSA and age, sex, race, or dilute bleach bath use. In comparison with pediatric patients presenting to the ED, AD patients had lower rates of MSSA susceptibility to doxycycline and MRSA susceptibility to trimethoprim-sulfamethoxazole (TMP-SMX).

Conclusions: First-generation cephalosporins remain appropriate empiric therapy for most pediatric AD patients. In patients with a history of MRSA, empiric doxycycline or TMP-SMX could be considered, given their high MRSA susceptibility rates.

Keywords: Staphylococcus aureus; SSTI; atopic dermatitis; pediatrics.