6- Dermatology (Skin infections: bacterial and fungal) Flashcards
folliculitis background
- Folliculitis means an inflammation or infection of the hair follicles of the skin.
- Due to obstruction in pilosebaceous glands +- infection
causes of folliculitis
- Infection e.g. S.aureus, fungal e.g. Candida spp, herpetic folliculitis (HSV)
- Immune system e.g. eosinophilic folliculitis
- Physical irritation
risk factors folliculitis
Uncut beard
Shaving ‘against the grain’
Thick hair
Excessive sweating
Skin abrasion
presentation of folliculitis
It may occur as a relatively trivial irritation - superficial folliculitis, or as a more deep-seated process involving the lower hair follicle
Symptoms
- Rash
- Scratch
- Pustule
- Erythema if deep folliculitis
- Regional draining of lymph nodes should be checked for adenitis ->mild folliculitis
- Folliculitis of eyelast- stye
management of folliculitis
- Avoid precipitating factors
- Use moisturizing shaving products
- Shave with the grain
- Good skin hygiene
- Superficial – antiseptics
- Deeper- oral antibiotics e.g. flucloxacillin, erythromycin
- May need surgery
cellulitis vs erysipelas
Cellulitis
- Acute, painful and potentially serious infection of the skin and subcutaneous tissues.
- Infection of the dermis and subcut tissue
Erysipelas
- Acute superficial from of cellulitis and involves the dermis and upper subcut tissue
which pathogens cause cellulitis and erysipelas
Streptococcous pyogens (group A Beta haemolytic) and staphylococcus aureus
rarely fungal
risk factors for cellulitis
- Previous cellulitis
- Immunosuppression
- Venous insuff
- Elder
- Alcohol dependency
- IV drug use
- Insect bites
- Obesity
- Athletes foot
- Diabetes
presentation of cellulitis
- Poorly demarcated borders
- Lower limb unilaterally
o Swelling (tumor)
o Erythema (rubor)
o Warmth (calor)
o Pain (dolor) - Sometimes precipitating skin lesion
- Blisters and bullae
- Systemic symptoms e.g. fever and malaise
- Red line streaking represents progression of infection to lymphatic system
- Crepitus
how can erysipelas be distinguished from cellulitis
distinguished from cellulitis by well-defined, red raised border
investigations for cellulitis
Bloods
- FBC
- CRP
- UEs
- LFTs
- Blood culture
Swabs
- culture fluids
Imaging
- US may be useful if abscess if suspected
Management of cellulitis
- Antibiotics e.g. Fluclox or benzylpenicillin
- Rest and elevate
- NSAIDS
- Clean wound (debride)
- Emollient
- Draw margins
complications of cellulitis
abscess and sepsis
impetigo background
Superficial bacterial skin infection
- Very contagious
- Classified as
o Non-bullous
o Bullous
bullous impetigo
- Epidermolytic toxins released by S.aureus break down proteins that hold skin cells together
- This causes fluid filled vesicles