Skin and soft tissue infection Flashcards
What are the most common types of rash?
- Papilloma
- Macules
- Papules
- Pustules
- Vesicles
- Ulceration
Describe a papilloma rash?
raised lesion (wart/verruca)
Describe a macules rash?
localised flat inflammation of skin
Describe a papules rash?
raised inflammation often spreads to neighbouring tissue
Describe a Pustules rash?
pus forms in skin often arise from hair follicle
Describe a vesicles rash?
fluid filled small blister lesion
describe a ulceration rash?
loss of epithelium as a result of inflammatory process, can get pus discharge
What is the most common pathogen causing pustules?
Staph Aureus
What is the most common cause of vesicle infection?
Herpes Simplex
Varicella Zoster
Enterovirus
What is the most common pathogen causing warts?
Human Papilloma Virus
What is the most common pathogens causing maculopapular rash?
enterovirus
Measles
Rubella
Parovirus B19
What are the layers of the skin and what infections occur in each?
Keratin (dermatophytes) Epidermis (impetigo) Hair structures (folliculitis and boils) Dermis (erysipelas) Subcutaneous (cellulitis)
What organisms cause cellulitis?
Streptococcus pyogenes
Staphylococcus aureus
What is the first line treatment for cellulitis?
Benzylpenicillin
Flucloxacillin
(to cover staphs and streps)
What are the life threatening skin infections?
Necrotising fasciitis
Fourniers Gangrene
Gas Gangrene
Toxic Shock Syndrome
What is the causative agent of Necrotising fasciitis?
Strep Pyogenes
What is the causative agent of Fourniers Gangrene?
Polymicrobial - can have gram pos or neg cause, often faecal origin
What is the causative agent of Gas Gangrene?
Clostridia
What is the causative agent of TSS?
Staph aureus
What are the risk factors for Fourniers Gangrene?
Obesity
diabetes
Peripheral vascular disease
What is the most common presentation of Gas Gangrene infection?
dirty wounds usually agriculture or military wounds
What are the red flags for skin/soft tissue infection?
- rapid onset
- previous skin trauma
- diabetes
- patient looks sick or in shock
- pain beyond the red area
- crepitus and gas on imaging
How are life threatening skin infections managed?
1) surgical debridement (can mean amputation)
2) hyperbaric oxygen chamber if gas gangrenes or other Clostridium infection
3) broad spec antibiotics (benzylpenicillin or flucloxacillin)
What is the most common Bacteria causing rashes?
Mycobacterium leprae
- affects Schwann cells
- can get varied reaction worst being tuberculoid leprosy
- treated with Dapsone
What fungal pathogens commonly cause skin infection and what are their symptoms and treatment?
Dermatophytes (ringworm) - itchy - peeling - loss of hair - often self-limiting Mycetoma - destructive chronic lesions - need amputation and high dose antifungals to treat
What are the common parasitic pathogens?
Ectoparasites - arthrpods - scabies - Human louse (Nits) Protozoa Helminths
What are antimicrobials are used for skin infection?
Ciprofloxacin
Clindamycin
What is the disadvantage of ciprofloxacin and clindamycin?
can cause C.Diff
What are the uses of Ciprofloxacin?
- those with penicillin allergy
- pseudomonas aeruginosa
- gram neg
What are the uses of Clindamycin?
- streptococci
- staphylococci
- gram pos anaerobes e.g. clostridium
