Skin And Soft Tissue Infections Flashcards
What are skin and soft tissue infections?
(SSTIs) are clinical entities of variable presentation, aetiology and severity that involve microbial invasion of the layers of the skin and underlying soft tissues
How do various cutaneous infections present and what are the most common infectious agents?
Impetigo: golden crusts, superficial, staph aureus
Erysipelas: infection of upper dermis, painful, red, fever, strep pyogenes
Cellulitis: diffuse skin infection involving deep dermis and subcut fat, erythemarous area with no distinct borders, fever, lymphadenopathy, strep pyogenes and staph aureus
Hair associated: folliculitis (pustular infection of hair follicle, staph aureas) furunculosis (boils; inflammatory nodule, staph aureus) carbuncles (multiple furuncles, constitutional symptoms common)
Necrotising fasciitis: rapid onset, erythema > oedema > severe unremitting pain. Haemorrhagic Bullard, necrosis, fever, hypotension, tachycardia, multiorgan failure, delirium
Type 1 is mixed infection eg diabetic foot, fournier’s gangrene. strep, staph, enterococcus, gram negative, clostridium
Type 2 strep pyogenes
Pyomyositis
Infection within striated muscle, fever, pain and woody induration, staph aureus
Septic bursitis
Peribursal cellulitis, swelling and warmth, fever, pain on movement, staph aureus
Infectious tenosynovitis
Infection of synovial sheaths, erythemarous swelling, tenderness, staph aureus
What are the major risk factors in developing skin and soft tissue infections?
Eczema, dermatitis, venous stasis, obesity, diabetes, abrasions, lymphoedema, IVDU, malignancy, immunocompromised
How do you treat the most common and most serious skin and soft tissue infections?
Impetigo: topical antibiotics or topical Tm + oral antibiotics
Erysipelas, cellulitis: antistaph and antistrep antibiotics
Hair associates: folliculitis = no treatment, furunculosis = no Tm or topical Ab, carbuncles may need surgery, IV Ab
Necrotising fasciitis: broad spectrum antibiotics and surgical review
Pyomyositis: drainage with antibiotic cover depending on gram stain and culture results
Infectious tenosynovitis: empirical Ab
How and why do special patient groups cutaneous infections whose causative agents are different from the normal population?
X
What are the most important toxin related syndromes affecting skin and soft tissue?
Toxic shock syndrome: usually staph, strep
Staph Features: fever, hypotension, macular rash, 3 of liver, blood, renal, GI, CNS, muscular
Strep features: erysipelas infection or necrotising fasciitis associated
Staphylococcal scalded skin syndrome
Widespread bullae, skin exfoliation
Panton Valentine Leucocidin toxin
Can cause SSTI and haemorrhagic pneumonia
Why is is early diagnosis and management of toxin related syndrome of skin and soft tissue important?
Can lead to endothelial leakage, haemodynamic shock, multi organ failure and possibly death
How do you recognise cannula associated infections, what are the most important causes and possible complications?
Starts as local SST inflammation, progresses to cellulitis and even tissue necrosis, common to have associated bacteraemia
Most commonly staph aureus
Blood culture +ve
Tm is to remove cannula, Abs for 14d
What are the different means of preventing infections in patients with peripheral venous cannula?
Do not leave unused cannula Do not insert unless using them Change every 72h Monitor for thrombophlebitis Use aseptic technique
What are the types of surgical wound infections?
Class 1: clean wound
Class 2: clean contaminated wound (resp, alimentary, genital or infected urinary systems entered but no unusual contamination)
Class 3: contaminated wound (open, fresh accidental wounds or gross spillage from the GI tract)
Class 4: infected wound (existing clinical infection, present before operation
What are the most common causes of surgical wound infections?
Staph aureus Coagulate negative staph Enterococcus E. coli Pseudomonas aeruginosa Enterobacter Streptococci Fungi Anaerobes
