[13] Impetigo Flashcards
What is impetigo?
A very common superficial infection of the skin
How can impetigo be divided?
- Bullous form
- Non-bullous form
What form of impetigo accounts for the majority of cases?
Non-bullous
How else can impetigo be classified?
- Primary
- Secondary
What is primary impetigo?
Where impetigo occurs in intact skin
What is secondary impetigo?
Where impetigo occurs in skin already affected by another condition
How is impetigo spread?
Direct contact with lesions or with nasal carriers
What is the incubation period of impetigo?
- 1-3 days in Streptococcus
- 4-10 days in Staphylococcus
What can cause lesions to spread in the individual?
Scratching
What are the common causative organisms of non-bullous impetigo?
- Staphylococcus aureus
- Streptococcus pyogenes
What is an increasingly common cause of non-bullous impetigo?
MRSA
What is bullous impetigo invariably caused by?
Staph. aureus
What are the risk factors for impetigo?
- Age 2-5
- Attending school or daycare
- Diabetes mellitus
- Dermatitis
- Immunodeficiency disorders
- Warm climate
How do non-bullous impetigo lesions present?
Tiny pustules or vesicles that evolve into honey-coloured crusted plaques
What is the typical size of the plaques in non-bullous impetigo?
< 2cm
Where do non-bullous impetigo lesions usually occur?
- Face (around mouth and nose)
- Extremities (at breaks in the skin)
How quickly can non-bullous impetigo spread on the skin?
Rapidly
What can occur due to auto-inoculation in non-bullous impetigo?
Satellite lesions
How much erythema and oedema will surround a non-bullous impetigo lesion?
Little to none
Is non-bullous impetigo itchy?
Can be
How may regional lymph nodes appear in non-bullous impetigo?
Enlarged
Describe bullous impetigo lesions
Thin roofed bullae that rupture spontaneously with little erythema
Where do bullous impetigo lesions usually appear?
- Face
- Trunk
- Extremities
- Buttocks
- Perineum
What is bullous impetigo more likely to occur alongside?
Other disease e.g. atopic eczema
