Impetigo (School Sores)

Last updated 13.02.13

 

Definition

-  Highly contagious rapidly spreading superficial skin infection caused by gram positive bacteria

 

Features

-  Typically in children but occurs at any age

-  Contagious

-  Outbreaks often occur in day care centres, kindergartens & schools

-  Transmitted by direct contact +/- objects

-  Without antibiotics purulent discharges may be infectious for weeks to months

-  Should not be infectious after 24hrs of Abx/Rx

-  Incubation period

-  1-3 days for Strep pyogenes

-  4-10 days for Staph aureus

-  Bullous or non-bullous (crusted)

Ecthyma is a variant of strep impetigo 

-  More common in patients with eczema, atopic dermatitis, etc.

 

Associated S/S

-  Lesions usually around nose & mouth

-  +/- local lymphadenopathy

-  Bullous impetigo

-  Yellow crusts & erosions

-  Prutitic or irritating

-  Not painful

-  Non-bullous (crusted) impetigo

-  Always Staph aureus

-  Mildly irritating blisters which erode rapidly to crusts

-  Ecthyma

-  Always Strep pyogenes

-  Ulcerative lesions

-  Single punched out ulcers

-  Usually on lower limbs

-  +/- Fever 

-  Usually no systemic S/S

 

Chin 1

 

Chin

 

Causes

-  Staph aureus most common

-  Strep pyogenes occasionally

-  More common in indigenous population

-  Can occur together

-  Group A Strep (GAS)

 

Complications

-  Glomerulonephritis in Strep pyogenes infections

-  Typically within 3-8 weeks

-  Scalded skin syndrome

 

Ix

-  Skin swab for MCS

-  +/- Nasal swab MCS if recurrent

 

Mx

-  Infectious risk

-  NOT a notifiable disease

-  Children should be excluded from school until 24hrs of Abx/Rx

-  Contact precautions: do not share toilet articles

-  Maintain good hand washing control

-  Sores on exposed surfaces must be covered with waterproof dressing

-  Blue Book contains Patient information sheet

-  Mx associated dermatosis if present: dermatitis, scabies, lice..

-  Mild or localized infection

-  Soap & water 8/24 to soften crusts

-  Mupirocin 2% ointment or cream topical to effected area 8/24 for 7 days

-  Widepsread or recurrent infection

-  Di/Flucloxacillin 500mg (children 12.5mg/kg) PO 6/24 7 days

-  If Penicillin hypersensitive use Cephalexin 1g (children 25mg/kg) PO 12/24 10 days

-  If Penicillin anaphylaxis use Roxithromycin 300mg PO Daily (children 4mg/kg up to 150mg PO BD) for 10 days

-  Confirmed or suspected Strep pypogenes

-  Soap & water BD to soften crusts

-  Abx

-   Benzylpenicillin 900mg IM single dose

-   Children 3-6kg 225mg

-   6-10kg 337.5mg

-   10-15kg 450mg

-   15-20kg 675mg

-   OR Phenoxymethylpenicillin 500mg (children 12.5mg/kg) PO 6/24 10 days

-   If Penicillin anaphylaxis use Roxithromycin 300mg PO Daily (children 4mg/kg up to 150mg PO BD) for 10 days

-  Recurrent or resistant Impetigo

-  Screen for nasal carriage of Staph aureus

-  Reswab for possible reinfection

-  +/- Decolonisation therapy for Staph aureus

 

 

 

References

 

eTG: Impetigo

Blue Book: Page 95, 2005

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Pic (chin)