Skin Infections and Infestations Flashcards
What is an infection?
Pathological state resulting from invasion of the body by pathogenic microorganisms
What lives on the skin?
Aerobic cocci - staphylococcus epidermidis and staphylococcus aureus
Corynebacterium and Propionibacterium
Yeats - Malassezia furfur
What are the signs of an infection?
Erythema, hot, tender, pus, exudate and fever
Does purulent skin problem mean there is infection?
No - can have sterile purulent
Signs of no infection - apyrexial, no rigors, long standing rash and no growth of pathogens on swab
What is impetigo?
Superficial skin infection
Most common bacterial skin infection in children
Can be bullous
Staph. aureus and strept pyogenes
What is the treatment for impetigo if localised?
Fusidic acid 2% cream 3-4 times daily for 5 days
Mupirocin 2% cream up to 3 times daily for 5 days (if MRSA)
What is the treatment for impetigo if widespread, severe or bullous?
Flucloxacillin 500mg oral 4 times daily for 7 days
Erythromycin 500mg oral 4 times daily for 7 days
What is the likely organism for cellulitis/ erysipelas?
Streptococcus pyogenes and staphylococcus aureus
What is the first choice antibiotic for cellulitis/ erysipelas?
Flucloxacillin 1g IV every 6hrs plus Benzylpenicillin 1.8g IV every 6hrs
What are some differential diagnosis for bacterial skin infections?
Deep vein thrombosis
Venous eczema
Allergic contact dermatitis
Necrotising fasciitis
What is the investigation and plan for bacterial infection?
Take swab - start antibiotics
Review after 48hrs - check skin swab result and switch according to sensitivities
If not better in a week then consider alternative diagnosis
Describe oedema blisters
Acute exacerbation of oedema can cause blisters to appear
Dorsum of feet
Often erythematous and can feel hot
Describe lipodermatosclerosis
If acute then can be hot and tender
Look for signs of venous disease and bilateral
Due to poor circulation in legs
Scarring and discolouration - hemosiderin depositions
What is the treatment for lipodermatosclerosis?
Treat underlying venous disease
Topical steroids
What are types of fungal infections?
Tinea (mould) - infection by dermatophyte
Candidiasis (yeast)