MRSA
MRSA is Staphylococcus aureus carrying the mec gene, which makes it resistant to beta-lactam antibiotics including Flucloxacillin. It is often resistant to other drug classes as well (DermNet). It is no more virulent than ordinary staph; the problem is that antibiotic choice is limited. Community-acquired MRSA (CA-MRSA) spreads where there is close skin contact and shared items, including nurseries. In children it mainly causes folliculitis, boils and Impetigo. Diagnosis needs a swab culture with antibiotic sensitivities.
MRSA [part-of] Staphylococcus aureus MRSA [opposes] Flucloxacillin MRSA [causes] Impetigo
MRSA in children with eczema. Among S. aureus isolates from people with Atopic Dermatitis, the MRSA share is 4–13 times higher than in healthy people, especially in children. People with severe AD have a higher risk of acquiring MRSA over time (Ogonowska, Front Microbiol 2021). In a New York paediatric dermatology clinic, 67.7% of MRSA isolates came from children with AD. Most of those (68.2%) were also mupirocin-resistant (Antonov, AAC 2015).
Conflict: [Ogonowska et al., Front Microbiol, 2021-01] reports a higher MRSA proportion in AD isolates, especially children. [Matiz et al., Pediatr Dermatol, 2011; title only, cited in Antonov 2015] reports that “children with atopic dermatitis appear less likely to be infected with community acquired MRSA” (San Diego). Rates vary widely by country and setting (Ogonowska’s own table ranges from 1 MRSA isolate in 114 Spanish AD children to 22% in Brazil). Unresolved — add to open_questions.
Atopic Dermatitis [relates] MRSA MRSA [relates] Mupirocin
Treatment and decolonisation. NICE NG190 and NICE NG153 say to consult a microbiologist if MRSA is suspected or confirmed in Infected Eczema or impetigo. For frequently recurring infection, they say to send skin and nasal swabs and consider Decolonisation. DermNet describes carrier treatment as Mupirocin or Fusidic Acid ointment in the nostrils 2–3 times daily for 3–5 days, plus antibacterial washes. Oral Clindamycin is an outpatient option for minor MRSA skin infection. Mupirocin decolonisation can fail where resistance is common, so Antonov et al. advise susceptibility testing first. For daily life, UKHSA requires no nursery exclusion for MRSA. DermNet’s hygiene advice is handwashing, not sharing towels, and covering sores. Good eczema control with Emollient Therapy and Topical Corticosteroids reduces the broken skin that staph needs.
Decolonisation [treats] MRSA NICE NG190 [regulates] MRSA Antimicrobial Resistance [causes] MRSA
Connections
- Staphylococcus aureus — resistant subset, source: Ogonowska 2021
- Infected Eczema — complicates antibiotic choice, source: NICE NG190
- Flucloxacillin — MRSA resists it, source: DermNet
- Decolonisation — nasal mupirocin/fusidic acid for carriers, source: DermNet; NICE NG153
- Mupirocin — decolonisation agent; resistance common in AD MRSA, source: Antonov 2015
- Clindamycin — oral option for minor MRSA skin infection, source: DermNet
- Antimicrobial Resistance — MRSA as a resistance outcome, source: DermNet
- Atopic Dermatitis — MRSA over-represented, source: Ogonowska 2021
- Impetigo — CA-MRSA presentation, source: DermNet