Skin and Soft Tissue Infections

Question 1

Impetigo

Most commonly affects?

Answer 1

Golden crusting weeping infection. children. Highly contagious, causing outbreaks.

Question 2

Bullous impetigo

Answer 2

As above but bullae form (large blister containing serous fluid). 10% of impetigo is bullous.

Question 3

Folliculitis

infects where?

where do you get it from?

Answer 3

Infection of the base of a hair follicle. Outbreaks occur in poorly maintained hot tubs and swimming pools

Question 4

Ecthyma

• secondary to what?

Answer 4

Crusted sores beneath which ulcers form. Often secondary to insect bites.

Question 5

Erysipelas

A superficial form of cellulitis.

Answer 5

70% in the lower extremities, 20% on face. It is the only one of these which is not caused by staph aureus. It is caused by Group A streptococcus a.k.a. streptococcus pyogenes

Question 6

Which one of the following is the only one not caused by Staph. Aureus?

Impetigo
Bullous impetigo
Folliculitis
Furuncle &; carbuncles
Ecthyma 
Paronychia
Erysipelas 

what is it caused by?

Answer 6

Erysipelas

It is caused by Group A streptococcus a.k.a. streptococcus

Question 7

• What is Scarlett fever?

• get characteristic rash called?
• desquamation occurs?

bacteria?

Answer 7

A disease from Group A strep where you get a sore throat, fever and a characteristic rash (named a scarlatiniform rash – red cheeks, strawberry tongue and spot on arms). Desquamation occurs after 2-5 days

Group A strep

Question 8

• What other syndrome can Scarlett fever cause?

• toxin?
• warned about this syndrome when using?

Answer 8

Toxic shock syndrome – TSST-1 exotoxin acts as a superantigen and causes systemic response. This is the disease you’re warned about when using very-absorbent tampons

Question 9

• What is scaled skin syndrome caused by?

Answer 9

An exfoliative infection caused by staph aureus which releases toxins and causes intradermal cleavage at the granular layer (no scarring afterwards)

Question 10

• What causes cellulitis?

Answer 10

1. Staphylococcus aureus

2. Group A strep

Question 11

• What is necrotising fasciitis?

• What type of necrotising fasciitis are there?
o Type 1 = bacteria?
o Type 2 = bacteria?

Answer 11

A rapidly progressing cellulitis with extensive necrosis of subcutaneous tissue and overlying skin.

o Type 1 = polymicrobial
o Type 2 = group A strep

Question 12

• How does necrotising fasciitis present?

first symptoms?

48 hours later?

Answer 12

o First symptoms = exquisitely tender, erythematous, swollen skin

o 48 hours later = skin breakdown and necrosis, area becomes anaesthetic due to thrombosis of small vessels and destruction of nerves.

Question 13

• What is anti-streptolysin O?

• what bacteria?

Answer 13

The exotoxin produced by group A strep, the main function of which is to cause haemolysis. You can test for it in the lab to confirm infection.

Question 14

• What is gas gangrene?

Caused by?

common after?

• What is the treatment?

Answer 14

An infection that produces gas in the tissues,

caused by clostridium perfringens.

After bowel surgery

1. Benzyl-penicillin
2. Gentamicin
3. Metronidazole
4. Surgery
5. Hyperbaric oxygen (used to reverse any anaerobic infections)

Question 15

• Who will Mycobactrium marinum infect?

Answer 15

Those who look after tropical fish

Question 16

• What causes anthrax?
• Who is at risk of anthrax?
• How do you treat anthrax?

Answer 16

Bacillus anthracis

wool workers, vets, farmers.

Benzyl-penicillin