Infections of Bone and Soft Tissue

Question 1

Impetigo

Answer 1

Very superficial skin infection, usually from S. aureus or S. pyogenes, highly contagious, honey-colored crusting, bullous impetigo has bullae and is usually caused by S. aureus, common in children

Question 2

Erysipelas

Answer 2

Infection involving upper dermis and superficial lymphatics, usually from S. pyogenes, presents with well-defined demarcation between infected and normal skin, common in children

Question 3

Cellulitis

Answer 3

Acute, painful, spreading infection of deeper dermis and subcutaneous tissues, usually from S. pyogenes or S. aureus, often starts with a break in the skin from trauma or other infection

Question 4

Abscess

Answer 4

Collection of pus from a walled-off infection within deeper layers of skin, almost always S. aureus, can be in any part of the body

Question 5

Necrotizing fasciitis

Answer 5

Deeper tissue injury, usually from anaerobic bacteria or S. pyogenes, results in crepitus from methane and CO2 production, “flesh-eating bacteria”, causes bullae and a purple color to the skin, most severe and rapidly spreading

Question 6

Staphylococcal scalded skin syndrome

Answer 6

Exotoxin destroys keratinocyte attachments in stratum granulosum only, characterized by fever and generalized erythematous rash with sloughing of the upper layers of the epidermis that heals completely, positive Nikolsky sign, seen in newborns and children, adults with renal insufficiency

Question 7

Most common pathogen in bone infections

Answer 7

Staphylococcus aureus

Question 8

Osteomyelitis

Answer 8

Pyogenic (typically bacterial), most common in children, presents with pain, decreased ROM, inability to bear weight, fever, elevated WBC with left shift, ESR, CRP

Question 9

Types of osteomyelitis

Answer 9

Hematogenous, contiguous-focus, direct-inoculation

Question 10

Hematogenous

Answer 10

Originated or transported by blood, vertebrae most common site, S. aureus most common

Question 11

Contigious-focus

Answer 11

Associated with previous surgery, trauma, wounds, or poor vascularity, usually bacterial

Question 12

Direct-inoculation

Answer 12

Associated with penetrating injuries or surgical contamination

Question 13

Risk factors for osteomyelitis

Answer 13

Recent trauma or surgery, immunocompromised patients, illicit IV drug use, poor vascular supply, systemic conditions like diabetes or sickle cell, peripheral neuropathy

Question 14

Treatment of acute osteomyelitis

Answer 14

Antibiotics

Question 15

Treatment of subacute osteomyelitis

Answer 15

Mostly antibiotics, some debriments

Question 16

Treatment of chronic osteomyelitis

Answer 16

Necrotizing bone, need debriments, possible amputation depending on severity

Question 17

Complications of osteomyelitis

Answer 17

Persistence or extension of infection, amputation, sepsis, malignant transformation