High prevalence of mupirocin resistance in Staphylococcus aureus isolates from a pediatric population.

Topical mupirocin is used widely to treat skin and soft tissue infections and to eradicate nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA). Few studies to date have characterized the rates of S. aureus mupirocin resistance in pediatric populations. We retrospectively studied 358 unique S. aureus isolates obtained from 249 children seen in a predominantly outpatient setting by the Division of Pediatric Dermatology at a major academic center in New York City between 1 May 2012 and 17 September 2013. Mupirocin resistance rates and the associated risk factors were determined using a logistic regression analysis. In our patient population, 19.3% of patients had mupirocin-resistant S. aureus isolates at the time of their first culture, and 22.1% of patients with S. aureus infection had a mupirocin-resistant isolate at some time during the study period. Overall, 31.3% of all S. aureus isolates collected during the study period were resistant to mupirocin. Prior mupirocin use was strongly correlated (odds ratio [OR] = 26.5; P = <0.001) with mupirocin resistance. Additional risk factors for mupirocin resistance included methicillin resistance, atopic dermatitis (AD), epidermolysis bullosa (EB), immunosuppression, and residence in northern Manhattan and the Bronx. Resistance to mupirocin is widespread in children with dermatologic complaints in the New York City area, and given the strong association with mupirocin exposure, it is likely that mupirocin use contributes to the increased resistance. Routine mupirocin testing may be important for MRSA decolonization strategies or the treatment of minor skin infections in children.

Pityriasis Lichenoides in Childhood: Review of Clinical Presentation and Treatment Options.

Pityriasis lichenoides (PL) is a skin condition of unclear etiology that occurs not uncommonly in childhood. It is often classified into the acute form, pityriasis lichenoides et varioliformis acuta (PLEVA), and the chronic form, pityriasis lichenoides chronica (PLC). We performed a comprehensive review of the English-language literature using the PubMed database of all cases of childhood PL reported from 1962 to 2014 and summarized the epidemiology, clinical features, treatment options, and prognosis of this condition in children. The proposed etiologies are discussed, including its association with infectious agents, medications, and immunizations and evidence for PL as a lymphoproliferative disorder. We found an average age of PL onset of 6.5 years, with a slight (61%) male predominance. We also found that PLEVA and PLC tend to occur with equal frequency and that, in many cases, there is clinical and histopathologic overlap between the two phenotypes. When systemic therapy is indicated, we propose that oral erythromycin and narrowband ultraviolet B phototherapy should be first-line treatment options for children with PL since they have been shown to be effective and well tolerated. In most cases, PL follows a benign course with no greater risk of cutaneous T-cell lymphoma, although given the rare case reports of transformation, long-term follow-up of these patients is recommended.