Impetigo Flashcards
Define impetigo and what are the types
Superficial bacterial infection of the skin:
Non-bullous: majority of cases (70%)
Bullous: formation of fluid filled lesions, usually >5mm in diameter
What is the aetiology of impetigo
Can develop as a primary infection in otherwise healthy skin OR a secondary complication of pre-existing skin conditions e.g. eczema, scabies, chickenpox
Transmission is via close contact with an infected person or indirectly via contaminated objects e.g. toys, clothing, towel
Organisms:
Staphylococcus aureus
Streptococcus pyogenes
Mixed
MRSA
What are the risk factors for impetigo
Skin trauma
Pre-existing skin disease e.g. eczema, scabies, chickenpox
Hot/humid weather
Poor hygiene
Crowding
What are the symptoms of non-bullous impetigo
Skin lesion:
- begins as thin walled vesicle/pustule → releases exudate
- Becomes a golden/brown crust
- most commonly peri-oral, peri-nasal, limbs, flexures
± satellite lesions
Mild pruritus
Severe: lymphadenopathy, fever
Otherwise asymptomatic
What are the symptoms of bullous impetigo
Skin lesion
- Flaccid, fluid-filled vesicles and blisters
- Blister ruptures → thin flat yellow/brown crust
- Most commonly flexures, face, trunk, limbs
Fever
Lymphadenopathy
Diarrhoea
Weakness
What are the differentials for impetigo
Cellulitis
Erysipelas
Scalded skin syndrome
Necrotising fasciitis
Candidiasis
Herpes simplex
Bullous pemphigoid
Pemphigus vulgaris
What are the investigations for impetigo
Clinical diagnosis
± Swab of lesion for MC&S (widespread cases, recurrent cases, or those that persist despite treatment)
What is the management for localised non-bullous impetigo
- Explain diagnosis and give information (British association of Dermatologists)
- Re-assure: heals without scarring
- Advice:
- Wash affected areas with soap and water
- Wash hands regularly
- Avoid scratching
- Avoid sharing towels, face cloths, care products
- Thoroughly clean toys and equipment - School exclusion recommended - until lesions are healed and crusted over OR 48h after Abx initiation
- Pharmacological:
First line: Hydrogen peroxide 1% cream (2-3x daily for 5 days)
Second line: topical fusidic acid
+ follow up
What is the management for widespread non-bullous and bullous impetigo
- Explain diagnosis and give information (British association of Dermatologists)
- Re-assure: heals without scarring
- Advice:
- Wash affected areas with soap and water
- Wash hands regularly
- Avoid scratching
- Avoid sharing towels, face cloths, care products
- Thoroughly clean toys and equipment - School exclusion recommended - until lesions are healed and crusted over OR 48h after Abx initiation
- Pharmacological:
First line: oral flucloxacillin 4x a day for 5 days - Consider referral
+ follow up
What are the complications of impetigo
Acute glomerulonephritis (streptococcal)
Cellulitis
Staphylococcal scalded skin syndrome
Lymphangitis
Osteomyelitis
Septic arthritis
Septicaemia
Scarlet fever, urticaria, erythema multiforme (streptococcal)
What is the prognosis of impetigo
Usually a self-limiting condition that takes 2-3 weeks to clear if untreated
Appropriate antibiotic treatment leads to rapid resolution infection, reducing the infective period
Relapse occurs often in people with underlying skin conditions e.g. eczema, and staphylococcal carriers
Impetigo can lead to life-threatening complications in some cases .g. immunosuppression, neonates