Flashcards in Dermatology Deck (216)
What is necrotizing fasciitis?
A fulminant, rapidly spreading infection with widespread tissue destruction through all tissues and planes
What is the mortality like for necrotising fasciitis?
What is type 1 necrotizing fasciitis caused by?
aerobic and anaerobic bacteria, seen post surgery or in diabetics
What is type 2 necrotizing fasciitis caused by?
group A streptococci (GAS), arising spontaneously
What are the symptoms of necrotizing fasciitis?
severe pain at site of initial infection with tissue necrosis
spreading infection across all planes
spreading erythema, pain and crepitus
fever, toxicity and pain
What do investigations show in necrotizing fasciitis?
increased CRP, ESR, WCC
What is the treatment for necrotizing fasciitis?
antibiotics (2 = benzylpenicillin and clindamycin, 1 = broad spectrum), surgical exploration, amputation
What is cellulitis?
infection of the deep subcutaneous layer
What are the symptoms of cellulitis?
hot and tender area, blisters, low grade fever, lymphedema, poorly demarcated margins
Where about does cellulitis affect and then spread to?
Starts in the lower leg and spreads upwards
How does the skin appear in erysipelas?
larger area with erythematous and sharply demarcated from normal skin
What causes cellulitis?
beta-haemolytic streptococcus, staphylococcus or MRSA
Investigations for cellulitis?
swab of toes, antistreptolysin O titre (ASOT) and antiDNAse B titre (ADB)
What is erysipelas?
a more superficial infection of cellulitis, often of the face, has a well demarcated edge
What is the treatment of cellulitis?
phenoxymethylpenicillin and flucloxacillin (IV or oral depending on how widespread), treat underlying cause, low dose antibiotic prophylaxis if recurrent to prevent further lymphatic damage
What is vasculitis?
Inflammatory disorder of blood vessels causing endothelial damage
What are the symptoms of vasculitis?
haemorrhagic papules, pustules, nodules, plaques that can erode and ulcerate, don't blanch from glass slide, fixed livedo reticularis pattern, pyrexia and arthralgia
What is leucocytoclastic vasculitis?
the most common cutaneous vasculitis affecting the small vessels
how does leucocytoclastic vasculitis usually appear?
on lower legs as a symmetrical palpable purpura
What is the treatment of vasculitis?
can resolve spontaneously, analgesia, support stockings, dapsone, prednisolone
What is the cause of leucocytoclastic vasculitis?
drugs, infection, inflammatory disease, malignant disease, idopathic
What causes pressure sores?
elderly, immobile, unconscious, paralysed from skin ischemia, sustained pressure over bony prominence
What are the four grades of pressure sores?
1 - non blanchable erythema of intact skin
2 - partial thickness skin loss of epidermis/dermis
3 - full thickness skin loss involving subcutaneous tissue, not fascia
4 - full thickness skin loss involving muscle, bone, tendons and joint capsule
What is the risk assessment scale called for pressure sores?
Norton scale and waterlow pressure sore risk assessment
What is the treatment for pressure sores?
bed rest, pillows, air filled cushions, pressure relieving mattress, regular turning, adequate nutrition, non irritant occlusive moist dressings, analgesics, plastic surgery, treat underling cause
What is eczema?
superficial skin inflammation with vesicles, redness, oedema, oozing, scaling and pruritis
What is the cause of eczema?
Atopy - initial selective activation of Th2 type CD4 lymphocytes in the skin which drive the inflammatory process
How common is eczema and who is most likely to have it?
In 5% of the population
10-20% of children
More likely if atopic
20-30% chance of passing onto child
What are some exacerbating factors of eczema?
dust mites, food allergies, pets, teething, strong detergents, chemicals, woollen clothes, lack of infection in infancy