Soft tissue, bone and joint infections

Question 1

Is staph aureus gram positive or negative? What colour are its colonies? Is it coagulase positive or negative?

Answer 1

Gram positive
Golden
Coagulase psoitive

Question 2

Is strep pyogenes gram positive or negative? Where does it preferentially colonise?

Answer 2

Positive

The pharynx

Question 3

Why does obesity predispose individuals to skin infections?

Answer 3

Infections can easily develop in the intertriginious folds

Question 4

What is the causative agent of impetigo and folliculitis? What is the most common treatment?

Answer 4

Staphylococcus aureus

Flucloxacillin

Question 5

What is furunculosis?

Answer 5

Deep inflammatory lesions progressing from folliculitis

Question 6

What is a carbuncle?

Answer 6

An infection which spreads into the subcutaneous layer, multiple abscesses develop which are separated by connective tissue

Question 7

What is acute paronchia?

Answer 7

Skin infection arising from a nail

Question 8

What is erysipelas? What is the most likely causative agent? What is the treatment?

Answer 8

Infection involving the upper dermis and extending into the superficial cutaneous lymphatics. Distinguished from from other forms of cutaneous infection by lesions raised above level of the surrounding skin (clear line of dermarcation. Group A streptococci. Penicillin.

Question 9

Who does staphylococcal scalded skin syndrome typically affect? How does it present clinically? How is it treated?

Answer 9

Seen in infants, young children and immunocompromised people. Begins with erythema and fever followed by large widespread bullae. Toxins released into the bloodstream from localised s, aureus infection. Flucloxacillin.

Question 10

Which single organism can necrotising fasciitis? What are the 3 stages of symptoms?

Answer 10

Group A streptococci. Early- pain appears disproportionate to injury + flu symptoms and thirst. Advanced symptoms- Swelling of the painful area, large dark blotches, mottled flaky appearance. Critical- Severe fall in blood pressure, toxic shock, unconsciousness

Question 11

What is gas gangrene? What is the most common causative agent? What is the ideal management?

Answer 11

Gangrene arising from devitalised wound.
Clostridium perfringens.
Surgery

Question 12

What are the definitions for the different types of SSI?

Answer 12

Classified as incisional or organ/space infection. Infection must occur within 30 days or one year if an implant is inserted. Assessment of the surgical site (purulent drainage), microbiology cultures + signs of infection

Question 13

What is septic arthritis and what are the most common causative agents?

Answer 13

Infection of joint spaces.

S. aureus, streptococci, gram negatives

Question 14

What are the most common causative agents of osteomyelitis?

Answer 14

S. aureus, h. influenzae, e. coli, p. aeruginosa, proteus mirabilis

Question 15

What are the 3 main routes for infection during septic arthritis?

Answer 15

Haematogenous route
Direct inoculation via trauma
Arthritis with associated tendonitis

Question 16

How is osteomyelitis managed?

Answer 16

With flucloxacillin for 4-6 weeks if acute and for at least 12 weeks if chronic

Question 17

What are the recommended antibiotics for mild, moderate and severe diabetic foot ulcers?

Answer 17

Mild- Fluclox
Moderate- co-amoxiclav
Severe- Piperacillin/tazobacatam

Question 18

What sort of lesions do HSV and VZV typically lead to?

Answer 18

Vesicular legions

Question 19

What is a dermatophyte infection? How are they typically treated?

Answer 19

Fungi invade dead tissue of the skin and appendages. With an antifungal such as nystatin suspension