Skin infections and infestations Flashcards
What is an infection?
The pathological state resulting from the invasion of the body by pathogenic microorganisms
We all have bacteria on the skin, but this does not mean we have an infection
What types of aerobic cocci live on our skin?
Staphylococcus epidermidis
Staphylococcus aureus
What are other aerobic and anaerobic bacteria that live on our skin?
Corynebacterium
Propionbacterium
What is a type of yeast that lives on our skin?
Malassezia furfur
What investigations are done for skin infections?
Skin swab for Microscopy, culture and sensitivities (M,C&S)
What are different skin investigations that can be done if clinically indicated?
Full blood count, ESR
U&Es, LFTs, Calcium, CRP
Skin biopsy
What is impetigo?
Superficial skin infection
Most common bacterial infection in children
What causes bacterial infections?
Staphylococcus aureus, Streptococcus pyogenes
How to treat localised impetigo?
Fusidic acid 2% cream 3-4 times daily for 5 days
Mupirocin 2% cream up to 3 times daily for 5 days (if MRSA)
How to treat widespread, severe, bullos impetigo?
Flucloxacillin 500mg oral four times daily for 7 days
Erythromycin 500mg oral four times daily for 7 days
What is cellulitis likely caused by?
Streptococcus pyogenes,
Staphylococcus aureus
What should first choice of antibiotic be in cellulitis?
Flucloxacillin 1g IV every 6 hours
plus
Benzylpenicillin 1.8g IV every 6 hours
What should be done if a bacterial infection is suspected?
Take swab Start antibiotics Review after ~48hrs check skin swab result switch according to sensitivities
What are oedema blisters?
Acute exacerbation of oedema
Dorsum of feet
Often erythematous
Can feel hot
What is lipodermatosclerosis?
If acute can be hot and tender
Look for signs of venous disease
Bilateral (often misdiagnosed as cellulitis)
What is the treatment of lipodermatosclerosis?
Treat underlying venous disease- Compression socks, foam scleropathy
Topical steroids
What are different fungal infections?
Tinea
Candidasis
What is tinea?
Infection by a dermatophyte
What does the name of tinea depend on?
The site affected
Where does ringworm or tinea corporis affect?
Body
Where does Tinea captis affect?
Head
Where does Tinea pedis affect?
Athelete’s foot
Where does Tinea cruris affect?
Groin
Where does Onychomycosis affect?
Nails
How is tinea infection of feet, body, hands or groin treated?
Topical treatment
Terbinafine or clotrimazole cream
How is tinea infection of scalp or nails treated?
Oral antifungals
How is candida treated?
Nystatin, Miconazole, Ketoconazole cream
How do you treat intertrigo?
Most cases are secondary to friction and irritating effect of sweat
Can be due to infection or skin condition
Emollient can often help
What are hand/finger warts caused by?
Human papilloma virus
What is some advice for people with warts?
Children with warts should NOT be excluded from physical activities, but should take care to minimise transmission
Cover the wart with a waterproof plaster when swimming
What are treatments for people with warts?
Normally not necessary:
Give patient a leaflet on viral warts
Treatments are not very effective
Wart paints and cryotherapy can stimulate immune system
Warts will go away when patient develops immunity against wart virus
What is molluscum contagiosum?
DNA pox virus
Umbilicated papules
May become secondarily infected
Will resolve when patient develops immunity
What is molluscum contagiosum?
5% Potassium Hydroxide
What are types of herpes simplex virus?
Herpes simplex 1 and 2
Cold sore
Eczema herpeticum
What is herpes simplex virus treated with?
Aciclovir
What are the treatments for scabies?
Permethrin cream top to toe for 8 hours
Two applications ~ 30g 1 week apart
Oral ivermectin can be used
Not licensed in UK
Treat all in household and close contacts so they aren’t reinfected- wash all bedding and clothing too
