Skin and soft tissue infection

Question 1

What are the most common types of rash?

Answer 1

• Papilloma
• Macules
• Papules
• Pustules
• Vesicles
• Ulceration

Question 2

Describe a papilloma rash?

Answer 2

raised lesion (wart/verruca)

Question 3

Describe a macules rash?

Answer 3

localised flat inflammation of skin

Question 4

Describe a papules rash?

Answer 4

raised inflammation often spreads to neighbouring tissue

Question 5

Describe a Pustules rash?

Answer 5

pus forms in skin often arise from hair follicle

Question 6

Describe a vesicles rash?

Answer 6

fluid filled small blister lesion

Question 7

describe a ulceration rash?

Answer 7

loss of epithelium as a result of inflammatory process, can get pus discharge

Question 8

What is the most common pathogen causing pustules?

Answer 8

Staph Aureus

Question 9

What is the most common cause of vesicle infection?

Answer 9

Herpes Simplex
Varicella Zoster
Enterovirus

Question 10

What is the most common pathogen causing warts?

Answer 10

Human Papilloma Virus

Question 11

What is the most common pathogens causing maculopapular rash?

Answer 11

enterovirus
Measles
Rubella
Parovirus B19

Question 12

What are the layers of the skin and what infections occur in each?

Answer 12

Keratin (dermatophytes)
Epidermis (impetigo)
Hair structures (folliculitis and boils)
Dermis (erysipelas)
Subcutaneous (cellulitis)

Question 13

What organisms cause cellulitis?

Answer 13

Streptococcus pyogenes

Staphylococcus aureus

Question 14

What is the first line treatment for cellulitis?

Answer 14

Benzylpenicillin
Flucloxacillin
(to cover staphs and streps)

Question 15

What are the life threatening skin infections?

Answer 15

Necrotising fasciitis
Fourniers Gangrene
Gas Gangrene
Toxic Shock Syndrome

Question 16

What is the causative agent of Necrotising fasciitis?

Answer 16

Strep Pyogenes

Question 17

What is the causative agent of Fourniers Gangrene?

Answer 17

Polymicrobial - can have gram pos or neg cause, often faecal origin

Question 18

What is the causative agent of Gas Gangrene?

Answer 18

Clostridia

Question 19

What is the causative agent of TSS?

Answer 19

Staph aureus

Question 20

What are the risk factors for Fourniers Gangrene?

Answer 20

Obesity
diabetes
Peripheral vascular disease

Question 21

What is the most common presentation of Gas Gangrene infection?

Answer 21

dirty wounds usually agriculture or military wounds

Question 22

What are the red flags for skin/soft tissue infection?

Answer 22

• rapid onset
• previous skin trauma
• diabetes
• patient looks sick or in shock
• pain beyond the red area
• crepitus and gas on imaging

Question 23

How are life threatening skin infections managed?

Answer 23

1) surgical debridement (can mean amputation)
2) hyperbaric oxygen chamber if gas gangrenes or other Clostridium infection
3) broad spec antibiotics (benzylpenicillin or flucloxacillin)

Question 24

What is the most common Bacteria causing rashes?

Answer 24

Mycobacterium leprae

• affects Schwann cells
• can get varied reaction worst being tuberculoid leprosy
• treated with Dapsone

Question 25

What fungal pathogens commonly cause skin infection and what are their symptoms and treatment?

Answer 25

Dermatophytes (ringworm)
- itchy 
- peeling 
- loss of hair
- often self-limiting 
Mycetoma 
- destructive chronic lesions
- need amputation and high dose antifungals to treat

Question 26

What are the common parasitic pathogens?

Answer 26

Ectoparasites 
- arthrpods
- scabies 
- Human louse (Nits)
Protozoa 
Helminths

Question 27

What are antimicrobials are used for skin infection?

Answer 27

Ciprofloxacin

Clindamycin

Question 28

What is the disadvantage of ciprofloxacin and clindamycin?

Answer 28

can cause C.Diff

Question 29

What are the uses of Ciprofloxacin?

Answer 29

• those with penicillin allergy
• pseudomonas aeruginosa
• gram neg

Question 30

What are the uses of Clindamycin?

Answer 30

• streptococci
• staphylococci
• gram pos anaerobes e.g. clostridium