Overview
Definition:
Methicillin-resistant Staphylococcus aureus (MRSA) decolonization refers to the process of eradicating MRSA carriage from an individual or environment to prevent recurrent infections and transmission
In pediatric recurrent skin infections, this is crucial for patients experiencing multiple episodes of skin and soft tissue infections (SSTIs) caused by MRSA, often associated with persistent carriage, particularly in the nasal passages.
Epidemiology:
MRSA colonization rates vary globally and within communities
In children, nasal carriage of S
aureus, including MRSA, is common, with rates potentially higher in those with recurrent skin infections, atopic dermatitis, or household contacts with MRSA
Recurrent SSTIs in children are frequently linked to persistent MRSA carriage.
Clinical Significance:
Recurrent MRSA skin infections in children can lead to significant morbidity, including pain, scarring, psychological distress, and functional impairment
Furthermore, persistent MRSA carriage increases the risk of invasive infections and transmission to vulnerable individuals
Effective decolonization is essential for preventing relapse, reducing antibiotic resistance, and improving quality of life.
Clinical Presentation
Symptoms:
Multiple episodes of skin lesions, such as boils, abscesses, cellulitis, or impetigo
Lesions may be recurrent in the same or different locations
Associated symptoms may include fever, localized pain, swelling, and drainage of purulent material.
Signs:
Visible skin lesions with characteristics of bacterial infection: erythema, warmth, tenderness, fluctuance (in abscesses), and purulent discharge
Chronic changes like scarring may be present from previous infections
Nasal examination might reveal visible crusting or discharge, though asymptomatic carriage is common.
Diagnostic Criteria:
Recurrent skin infection is typically defined as three or more distinct episodes of skin and soft tissue infection within a 12-month period
Confirmation of MRSA as the causative agent is made through laboratory culture and susceptibility testing of purulent material from skin lesions.
Diagnostic Approach
History Taking:
Detailed history of previous skin infections: number, location, treatment, and culture results
Family history of MRSA colonization or infection
Presence of risk factors: atopic dermatitis, close contact with individuals with MRSA, participation in contact sports, daycare or school attendance
Review of hygiene practices
Previous decolonization attempts and their outcomes.
Physical Examination:
Thorough skin examination to assess current lesions and identify any residual signs of infection or scarring
Examination of nasal mucosa for crusting or discharge
Assessment of atopic dermatitis severity if present.
Investigations:
Cultures: Wound cultures from active lesions for bacterial identification and antibiotic susceptibility testing
Nasal swabs for MRSA screening (culture or PCR) to identify carriage
If invasive disease is suspected, blood cultures and other relevant cultures should be obtained.
Differential Diagnosis:
Recurrent bacterial infections by MSSA or other bacteria
Fungal skin infections
Viral exanthems
Allergic contact dermatitis
Recurrent insect bites leading to secondary bacterial infection
Atopic dermatitis flares.
Management
Initial Management:
For active infections: Incision and drainage of abscesses
Appropriate systemic or topical antibiotics based on culture and sensitivity results for the active infection
Good hygiene practices: frequent handwashing, keeping wounds clean and covered.
Medical Management:
Decolonization protocols aim to reduce or eliminate MRSA carriage
Common strategies include: 1
Topical Intranasal Antibiotics: Mupirocin 2% ointment applied intranasally three times daily for 5-10 days is the first-line treatment for nasal carriage
Besifloxacin or retapamulin can be alternatives
2
Topical Antiseptics: Chlorhexidine (e.g., 2% soap or wash) or dilute bleach baths (e.g., 1/4 cup household bleach in a full bathtub of water for 5-10 minutes, 2-3 times weekly) for skin cleansing
3
Oral Antibiotics: Used judiciously for patients with recurrent infections refractory to topical therapy or with extensive carriage
Options may include rifampicin (10 mg/kg/day divided into two doses for 5-10 days, often in combination with another agent like trimethoprim-sulfamethoxazole or minocycline) or trimethoprim-sulfamethoxazole (10 mg/kg/day divided into two doses for 10-14 days, if susceptible)
Resistance patterns must be considered
Consider treatment of household contacts if recurrent transmission is suspected.
Surgical Management:
Primarily for active infections: Incision and drainage (I&D) of purulent collections like abscesses or carbuncles
Surgical excision may be considered for chronic draining sinuses or recurrent carbuncles.
Supportive Care:
Education on hygiene practices
Management of underlying conditions like atopic dermatitis to reduce skin barrier breakdown
Regular follow-up to assess treatment efficacy and adherence
Environmental cleaning protocols, especially in daycare or school settings if feasible and indicated.
Complications
Early Complications:
Treatment failure, leading to persistent infections
Development of antibiotic resistance
Allergic reactions to topical or oral agents.
Late Complications:
Spread of infection to deeper tissues or bloodstream (bacteremia, sepsis)
Osteomyelitis or septic arthritis if joint is involved
Chronic scarring and disfigurement
Psychological impact of recurrent infections.
Prevention Strategies:
Strict adherence to prescribed decolonization regimens
Prompt treatment of active infections
Education on hygiene and wound care
Consideration of household and close contact screening and treatment if indicated
Regular follow-up to monitor for recurrence and treatment effectiveness.
Prognosis
Factors Affecting Prognosis:
Adherence to treatment
Presence of underlying immunocompromise or comorbidities
Strain of MRSA and its susceptibility patterns
Environmental factors and community prevalence
Effectiveness of decolonization regimen.
Outcomes:
With successful decolonization and appropriate management of active infections, prognosis is generally good, with a significant reduction in recurrent infections
However, some individuals may remain colonized and experience intermittent recurrences.
Follow Up:
Regular follow-up appointments are crucial, especially for children with frequent recurrences, to monitor for treatment adherence, assess the effectiveness of decolonization, and re-culture if necessary
The duration of follow-up depends on the severity and frequency of infections.
Key Points
Exam Focus:
Recognize indications for MRSA decolonization: recurrent SSTIs, especially in children with atopic dermatitis
First-line nasal decolonization is intranasal mupirocin
Chlorhexidine washes/bleach baths are useful for skin
Oral antibiotics (rifampicin, TMP-SMX) are reserved for refractory cases or extensive carriage.
Clinical Pearls:
Always culture recurrent skin infections to confirm MRSA and guide therapy
Consider treating household contacts if a clear transmission chain is suspected
Patient education on hygiene is paramount
Multidisciplinary approach involving dermatology, infectious diseases, and primary care is often beneficial.
Common Mistakes:
Failure to screen for nasal carriage in recurrent MRSA SSTIs
Inadequate duration or adherence to decolonization regimens
Over-reliance on oral antibiotics without addressing carriage
Not considering treatment of household contacts
Misinterpreting colonization as an active infection.