Cellulitis Flashcards
What can predisposose to skin infections
Injury, surgery, diabetic foot ulcers and burns
WHat organism typically causes folliculitis
S. Aureus
What are the virulence factors of S. Aureus
Will adhere with adhesins, prevents phagocytosis with capsule, will inhibit neutrophil migration with CHIP, Can form biofilm, can kill cells with heamolysins or leukocidins and all lead to abscess formation
What is the definition of impetigo
Bulloid, crusted or pastular defined lesions on the skin, usually the head and neck
What are the causes of impetigo, erysipelas and cellulitis
Staph and Grp A Strep
What is the definition of Erysipelas
Is a rapidly spreading superficial infection with well defined borders plus fever and pain
What is the definition of Cellulitis
Same as Erysipelas yet extends to the subcutaneous fat
What organisms cause Necritising Fascititis
Strep pyogenes and Clostridium perfingens
What is the definition of Necritising Fascititis
Is a rapidly spreading infecting along the fascia of muscles that induces necrosis, can be very severe and must require amputation to prevent spread
What are some virulence factors of Grp A strep
Protein M (Rhumatic Fever), heamolysin, hyaluronidase (ECM degradation), C5a peptidase, DNAase to overcome NETs, streptolysins and leukocidins, superantigens (TSS), capsule
What is the mechanism by which Clostridium can cause gas gangrene
Will be able to grow in vitalised tissue (anaerobic) and enzymes produce gas, that can lead to tissue damage and further spread of bacteria
What species of Fungi can induce Tinea
The Dermatophytes which include microsporum, epidermophyton and trichomophyton
WHat are species of arthropods that can induce skin lesions
Ticks, mites, lice and insects
What are the most common viruses that can cause skin lessions
VZV and HSV1/2
