skin infections Flashcards
causes of skin infections
- bacterial
- viral
- fungal
- parasitic
skin red flags
- Severe systemic illness – feeling very unwell, abnormal temp, rigors, anuria
- Drowsiness
- Photo sensitivity
- Non-blanching rash
- Stiff neck
- Severe headache/other pain
- Vomiting
- Worsening Sx
bacterial skin infections caused by staph aureus or group A streptococcus
- Impetigo
- Erysipelas
- Cellulitis
- Wound infections
- Infected bites and stings
- Diabetic foot infection
impetigo
- Contagious, common infection
- Often in young children
- Starts with red sores (nonbullous) or blisters (bullous), which burst and leave crusty patches
- These inc in size and can spread
Tx for impetigo
hydrogen peroxide 1%
fuscidic acid 2%
cellulitis
- acute bacterial infection of the dermis and SC tissue
- Sx include acute onset of pain, warmth, swelling, and erythema
- blisters may form
- most common in lower limbs
- mostly bacterial through break in the skin
erysipelas
- form of cellulitis
- but affects upper dermis
- usually on on face/limbs
- Group A Streptococcus
- pt unwell before rash develops
RF for cellulitis
- Lymphoedema (poor lymphatic drainage)
- Leg oedema (elderly)
- Venous insufficiency and Hx of venous surgery
- Immunocompromised
- Existing wound
- Drug user
- Obesity
- Pregnancy
- Have had cellulitis before
complications of cellulitis
ACUTE COMPLICATIONS:
- systemically unwell - tachycardia, hypotension, tachypnoea, confusion
- sepsis
- deep-seated infection, such as necrotising fasciitis, abscesses
CHRONIC COMPLICATIONS:
- persistent leg ulceration
- lymphoedema
- recurrent cellulitis
differential diagnosis of cellulitis
COMMON CONDITIONS (unilateral red/swelling):
– Erysipelas
– Thrombophlebitis
– DVT
– Septic arthritis
– Acute gout
CHRONIC CONDITIONS (usually bilateral but worse on 1 side could be cellulitis):
– Varicose eczema/venous insufficiency
– Lymphoedema
– Oedema with blisters
Tx for cellulitis in primary care
1st line:
- flucloxacillin 500mg - 1g QDS
pen allergy:
- clarithromycin 500mg BD or erythromycin (preg) 500mg QDS
all 5-7 days
Tx for cellulitis in secondary care
1st line
- flucloxacillin PO/IV 1g-2g QDS
2nd line
- doxycycline PO
- clindamycin PO/IV
Tx for MRSA causing cellulitis
doxycycline PO
or
daptomycin IV
when to refer to hospital with cellulitis
- severely unwell
- infection near the eyes or nose
- could have uncommon pathogens
- spreading infection that is not responding to oral ABX
- can’t take oral ABX
supportive Tx for cellulitis
- paracetamol, ibuprofen for pain
- raise body apart on pillow/chair when sitting/lying to reduce swelling
- regular moving joint near affected body part to prevent stiffness
- fluids to avoid dehydration
- DON’T wear compression stockings until resolved
prevention of cellulitis reoccurrence
- keep skin clean and well moisturised
- clean cuts/wounds, or use antiseptic cream
- prevent cuts and scrapes by wearing app clothing/shoes
- manage breaks in the skin which can become entry for organisms
- treat eczema/tinea pedis/leg ulcer
- manage venous insufficiency, compression stockings after acute cellulitis resolved
- consider referring lymphoedema to specialist
- if recurrent episodes of cellulitis (2+ same site in 1yr), consider referral to secondary care for prophylactic ABX
signs of infection in wounds/bites/scrathes/stings
swelling
redness
pus
systemic illness
What are infected wounds/bites/scratches mostly caused by?
staph aureus
bite Tx/prophylaxis
co-amoxiclav
doxycycline AND metronidazole (pen allergy)
What is Lyme disease?
bacterial disease spread by ticks
not all ticks carry Lyme disease
Sx of Lyme disease
- bullseye rash
- 1-4 weeks after bite
- can have systemic Sx days/weeks
- Sx develop over years
- fatigue, aches, loss of energy
How to avoid tick bites?
- Cover skin when walking outdoors
- Use DEET repellant
- Stay on clear paths
Tx for Lyme disease
doxycycline 100mg BD
alt = amoxicillin
examples of viral skin infections
- Coldsores
- Chickenpox
- Shingles
- Molluscum contagiosum
- Hand, foot and mouth disease
- Measles
- Warts
- Rubella
Tx for chicken pox and shingles
1st line = aciclovir 800mg x5 daily 7 days
2nd line = famciclovir
common causes of fungal skin infections
dermatophytes
Candida
RF for fungal skin infections
- hot/humid environments
- wearing tight clothing
- obesity
- recent ABX Tx
management of fungal skin infections
- self-care
- Tx with topical antifungal (terbinafine, an imidazole if mild/non-extensive disease or Candida possible)
- inflammation - topical corticosteroid
- severe or extensive disease – consider oral antifungal e.g. terbinafine, traconazole
- management to reduce the risk of re-infection
- take skin sampling where app
- consider referral to dermatology if severe/extensive disease
