Soft Tissue and Bone Infections

Question 1

What 2 things make up soft tissue?

Answer 1

Skin

Connective tissues

Question 2

Define impetigo

Which bacteria?

Answer 2

Skin infection of the epidermis

Staphylococcal

Question 3

Define erysipelas

Which bacteria?

Answer 3

Skin infection of the epidermis

Streptococcal

Question 4

Define cellulitis

Which bacteria?

Answer 4

Skin infection of the dermis +/- subcutaneous fat

Staphylococcal or streptococcal

Question 5

Define furuncle

Which bacteria?

Answer 5

Deep infection of a hair follicle

Staphylococcal

Question 6

Define carbuncle

Which bacteria?

Answer 6

Connective collection of furuncles

Staphylococcal

Question 7

Define necrotising fasciitis

Which bacteria?

Answer 7

Deep infection of the fascia +/- muscle

Streptococcal or mixed

Question 8

Name some viruses that can infect the skin

Answer 8

Viral warts

Herpes

Viral exanthems (chickenpox, shingles, measles)

Molluscum contagiosum

Smallpox

Question 9

What organism causes athlete’s foot?

Answer 9

Tinea pedis fungus

Question 10

What are coagulase-negative Staphylococci?

Answer 10

Staph species that are not staph aureus

Lack an enzyme called coagulase and therefore less aggressive to humans

Question 11

List the 8 steps of bacterial pathogenesis in SSTIs

Answer 11

Access

Adherence

Invasion

Multiplication

Evasion

Resistance

Damage

Transmission

Question 12

What 6 things should be used to describe a skin lesion or rash?

Answer 12

Shape

Size

Edge

Colour

Surface

Distribution

Question 13

How could you tell if someone was infected with a superficial streptococcal?

What infection is this likely to be?

Answer 13

The lesion would be red and well demarcated (obvious border)

Erysipelas

Question 14

What is cutaneous leishmaniasis?

Answer 14

Parasitic skin infection

Raised wound edge

South America

Question 15

Name the drug that can be administered in viral skin infections

Answer 15

Aciclovir

chicken pox, herpes, shingles

Question 16

What is often the first line treatment in MRSA?

Answer 16

Flucloxacillin

Question 17

What can be given to treat impetigo

Answer 17

Topical fuscidin

Question 18

What is first line treatment for Streptococcus infections?

Answer 18

Penicillin

e.g. benpen.

Question 19

What is terbinafine used for?

Answer 19

Topical fungal infections

Can be PO if needed

Question 20

Define osteomyelitis

Answer 20

Infection of bone

Question 21

Define septic arthritis

Answer 21

Infection of joints

Question 22

Define prosthetic joint infection

Answer 22

Infection of an artificial joint replacement

Question 23

Which microbe is most likely to be responsible for a bone infection?

2nd most likely?

Answer 23

Staphylococcus aureus

Streptococci (B-haemolytic, strep. pneumoniae

Question 24

List some risk factors for developing a joint or soft tissue infection

Answer 24

Trauma

Medical procedures

Skin ulcers

IV devices, IVDU (haematogenous dissemination)

Immunosuppression - diabetes, renal failure, sickle cell disease

Question 25

What is a sequestrum?

Answer 25

A part of bone that becomes necrotic due to infection

Question 26

What is an involucrum?

Answer 26

New bone formation outside the sequestrum

Question 27

What is the name for a hole in the involucrum that allows pus from the sequestrum to leave the site of infection?

Answer 27

Cloacae

Question 28

Why can it be hard for Abx and the immune system to penetrate a bone infection?

Answer 28

Because the bacteria sits in an organic matrix across a surface - causes a biofilm

Question 29

What causes a discharging sinus? How would it present?

Answer 29

Infection and pus from cloacae causes skin necrosis

Question 30

How might a patient with osteomyelitis present?

Answer 30

Pain Redness Swelling Warmth Loss of function Fever Pathological fractures Discharging sinuses

Question 31

How might a patient with septic arthritis present?

Answer 31

Pain Redness Swelling Warmth Loss of function Fever Damage to articular surfaces

Question 32

What empirical antibiotics would be given for bone infections? Which bacteria are they best at treating?

Answer 32

IV flucloxacillin Staphylococcal IV benzylpenicillin Streptococcal