impetigo Flashcards
what is impetigo?
Impetigo is a highly contagious superficial epidermal infection of the skin primarily caused by Staphylococcal and Streptococcal bacteria.
causes of impetigo?
Staphylococcus aureus (most common)
Group A beta haemolytic Streptococcus (Streptococcus pyogenes)
In 10% of cases, both bacteria are present.
pathophysiology of impetigo?
These bacteria can invade the skin through minor cuts, insect bites, or abrasions, leading to infection.
Impetigo is very contagious and is spread through direct contact, with lesions appearing 4-10 days after contact.
Bullous lesions are almost exclusively caused by Staphylococcus aureus, as this bacteria produces an exotoxin targeting desmoglein - 1 (an epithelial intercellular adhesion molecule).
RF for impetigo?
Pre-existing skin conditions (i.e. eczema, cuts, burns, scabies)
Immunosuppression
Direct contact with an infected individual
Environmental factors such as crowding, humidity and poor hygiene.
classifications of impetigo?
Bullous: The child will have fluid filled lesions greater than 1 cm in diameter
Non-bullous: This is more common, and the child will not have bullae
primary vs secondary impetigo?
Primary: Infection occurs in otherwise normal skin.
Secondary: Infection is related to an underlying skin condition (i.e. eczema) or breach to the skin barrier (i.e. bite or cut).
features of impetigo?
Erythematous macule that vesiculates or pustulates
Superficial erosion with a characteristic golden crust
Impetigo may be bullous (causing large blisters) or non-bullous (causing sores)
Patches may be itchy or painful
what is this?
impetigo
ix for impetigo?
A skin swab may be necessary for microscopy, culture, and sensitivity, particularly in cases resistant to treatment or in the context of recurrent infections.
mx for Localised non-bullous impetigo?
topical treatment with hydrogen peroxide 1% cream (apply two or three times daily for 5 days) is first-line
If unsuitable, second-line options include fusidic acid or mupirocin (if fusidic acid resistance)
mx for Widespread non-bullous impetigo?
Topical (fusidic acid/mupirocin) or oral antibiotics for 5 days, such as flucloxacillin
Clarithromycin (penicillin-allergic) or erythromycin (pregnancy) are alternatives
mx for Bullous impetigo, or impetigo in those systemically unwell or at high risk of complications?
Oral antibiotics as above for up to 7 days
hygiene measures for impetigo?
Avoid scratching the lesions
Cover the affected areas and wash hands with soap and water
Avoid sharing toys and towels whilst the infection is active
school rules for impetigo?
Children should be off school until all lesions are healed or until 48 hours after starting treatment.
when to refer for impetigo?
Suspected complications of impetigo (sepsis, glomerulonephritis, or deeper soft tissue infection)
The patient is immunocompromised and infection is widespread
