Skin Infections And Infestations Flashcards
Signs of skin infection (6)
Erythema
Hot
Tender
Pus
Exudate
Fever
Investigations for skin infections
Skin swab for microscopy, culture and sensitivities (MC&S)
If clinically indicated:
- FBC, ESR
- U&Es, LFTs, calcium, CRP
- skin biopsy
What is a typical presentation of eczema
Rash since childhood which is the same on both sides
What is impetigo (what bacteria causes it)
Superficial skin infection (most common skin infection seen in children)
Can be bulbous
staph. Aureus + strep. Pyogenes
What is the classic presentation of impetigo (3)
Crusting (often described as a honey yellow colour)
- starts in one small area and spreads over skin due to scratching
Erythema
Generally not unwell
What is the treatment for impetigo (localised and widespread)
Localised:
- fusidic acid cream 3-4 times daily for 5 days
- mupirocin cream upto 3x daily for 5 days (if MRSA)
If widespread, severe, bullous:
- antibiotics
- flucloxacillin oral 4 times daily for 7 days
- erythromycin oral 4 times daily for 7 days
What is cellulitis/erysipelas, what organism causes them
Erysipelas = superficial infection
Cellulitis = deeper tissues
Strep pyogenes or staph aureus
What are the 1st choice antibiotics (if severe)
Flucloxacillin IV
PLUS benzylpenicillin IV
What is the generic treatment for bacterial skin infections
Take swab
Start antibiotics
Review after 48hrs:
- check skin swab result
- switch according to sensitivities
If not better in a week consider alternative diagnosis
What would indicate oedema blisters as opposed to cellulitis
If blisters are just on one leg
What are oedema blisters
Acute exacerbation of oedema
Dorsum of feet
Often erythematous
Can feel hot
What sign would indicate an infection is fungal as opposed to bacterial
Fungal infections are usually unilateral and localised (if bilateral most likely not fungal)
What is tinea?
Infection by a dermatophyte (mould)
What is the treatment for tinea
Infection of feet, body, hands or groin usually responds to topical treatment (Terbinafine or clotrimazole cream)
Infection of scalp or nails requires oral Antifungals
(Check and treat other family members)
When to determine whether eczema or tinea
History, distribution (eczema is symmetrical and VERY common)
Steroid treatment given for suspected eczema can mask tinea symptoms (if in doubt take skin scrapings)
(Tinea is mould so likes cool damp places)
What is the outcome of herpes zoster virus (chicken pox)
Self-limiting illness
Once you’ve had it you usually don’t get it again
Secondary infection in adulthood = shingles
Where are the typical sites of scabies
Nipples, genitals, feet, backs of hands/wrists (see photo)
(CLUE: penile nodules - not many other rashes causes this)
