Impetigo

Disclaimer These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline.  Read the full PCH Emergency Department disclaimer.

Aim 

To guide PCH Emergency Department (ED) staff with the assessment and management of impetigo.

Background 

• Impetigo is a contagious bacterial infection of the superficial layers of the epidermis
• Impetigo is the most common bacterial skin infection in children. Commonly called school sores

There are two general types:

• Non-bullous Impetigo (impetigo infectiosa) is most common between the ages of 2 and 5 years. It has a tendency to occur for the nares and around the mouth, and also commonly occurs on the extremities at sites of trauma. Impetigo may develop at sites affected by chicken pox, burns, insect bites, abrasions and lacerations. There is usually little or no pain and no constitutional / systemic symptoms.
• Bullous Impetigo is most commonly an infection of neonates and typically occurs on the trunk and extremities. Flaccid bullae occur which rupture easily. This condition resembles a localised form of Staphylococcal Scalded Skin Syndrome (SSSS).

Pathogens

Staphylococcus aureus and Streptococcus pyogenes (either individually or in combination).

• Consider MRSA

Complications

These are relatively uncommon but include:

• Lymphadenitis
• Scarlet fever
• Osteomyelitis
• Septic arthritis
• Pneumonia
• Septicaemia
• Post-streptococcal glomerulonephritis - rarely and does not appear to be influenced by antibiotic treatment.

Impetigo often spreads rapidly, and the infection is generally more severe in children suffering atopic dermatitis (and other dermatological conditions).

Assessment

Examination

• Lesions typically begin with a single 2-4mm erythematous macule, which rapidly turns into a vesicle or pustule, which ruptures leaving a honey-coloured crusted exudate.
• Spread to adjacent skin can be rapid.
• Resolution without scarring is to be expected.

Investigations

• Cultures of the lesions are only required if initial treatment has failed. If performed, swabs should be obtained from beneath the lifted edge of a crusted lesion.
• Nasal swabs (and occasionally swabs from the axillae and perineum) are helpful in cases of recurrent impetigo to identify nasal (or other) carriage of Staphylococcus aureus.

Differential diagnoses

• Viral infections (e.g. Herpes simplex virus, Varicella zoster)
• Fungal infections
• Parasitic infections (e.g. scabies)
• Eczema / atopic dermatitis

Secondary impetigo can occur with viral rashes and eczema / dermatitis.

Management

Oral antibiotics are not always required – topical antibiotics may be suitable for mild cases.

Initial management

• Topical Mupirocin 2% ointment (rather than cream) applied to affected areas TDS (8 hourly) for 7 days is the preferred treatment for limited disease
• Oral antibiotics are indicated for
  • more extensive disease
  • recurrent impetigo
  • post-streptococcal glomerulonephritis (PSGN)
  • in patients at high risk of acute rheumatic fever (ARF) and / or
  • if the patient is systemically unwell
• Choice of antibiotic should be guided by local sensitivity patterns and the child's likelihood of tolerating the antibiotic.
• For antibiotics information refer to Skin and Soft Tissue Infections (Paediatric Empiric Guidelines) – ChAMP

Health information (for carers)

Hygiene Issues

• Soap and water cleansing, air-drying whilst at home, use of child’s own face wash towels, importance of hand washing.
  • These simple things may not be known by parents and should be reinforced prior to discharge.
• The use of disinfectant solutions or medicated soaps probably gives no advantage over plain soap and water and drying.
• In recurrent cases associated with nasal and other site carriage, chlorhexidine body wash may be preferred, as part of a broad eradication regimen – consultation with microbiology is recommended in this situation.

School / Day Care Exclusion

• Exclude from school / daycare until lesions are healed and crusted over and no longer weeping, or until 24 hours after commencing antibiotic (topical or systemic) treatment.
• Whilst at school, lesions on exposed areas should be covered with a waterproof dressing.

Nursing

• Complete and record a full set of observations on the Observation and Response Tool and record additional information on the Clinical Comments chart.
• Implement Standard and Contact Precautions. Refer to Standard and Transmission Based Precautions – Infection Prevention and Control Manual (internal WA Health only)

Isolation

Single-room isolation is not required for skin infections.

Bibliography

1. Epps RE. Impetigo in pediatrics. Cutis. 2004 May;73(5 Suppl):25-6
2. Koning S, Verhagen AP, van Suijlekom-Smit LW, Morris A, Butler CC, van der Wouden JC. Interventions for impetigo. Cochrane Database Syst Rev. 2004;(2):CD003261
3. Communicable Disease Guidelines for teachers, child care workers, local government authorities, and medical practitioners. 2002 Edition. WA Health Department. 
4. Staying Healthy in Child Care – Preventing infectious diseases in child care – Third Edition. 2003. National Health and Medical Research Council (NHMRC). Available from: Building a Healthy Australia  NHMRC website
5. eTG complete [Internet]. Melbourne: Therapeutic Guidelines Limited; May 2022. Accessed February 2023

Endorsed by:	Nurse, Co-director, Surgical Services	Date:	Feb 2023
		Review date:	Feb 2026

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