Abscess

Question 1

What is an abscess?

Answer 1

Collection of pus in skin, lungs, brain, teeth, kidneys and tonsils.

Question 2

What is the aetiology of abscesses?

Answer 2

• Bacteria: S. aureus, MRSA
• Parasites: rarely; dracunculiasis and myiasis
• Foreign substances

Question 3

What is the pathophysiology of abscesses?

Answer 3

Infective organism/foreign material causes damage and kills local cells, resulting in relase of cytokines. Cytokines trigger an inflammatory response and formation of an abscess. This collection is encapsulated by surrounding cells in an attempt to prevent the abscess from spreading.

Question 4

What is an empyema?

Answer 4

Accumulations of pus in a pre-existing (rather than newly formed) cavity.

Question 5

How does cellulitis differ from abscess?

Answer 5

Cellulitis is not often associated with purulence.

Question 6

What is the epidemiology of abscesses: Most common type?

Answer 6

MRSA is most common.

Question 7

What are the signs and symptoms of abscess?

Answer 7

Erythema, swelling, tenderness, loss of function. May also be associated with fever.

Question 8

What are the investigations for abscess?

Answer 8

Diagnosis of skin abscesses is clinical. Internal abscesses are diagnosed by USS or CT. CT is more useful in deeper abscesses such as anus. Would culture is usually unnecessary

Question 9

How are abscesses treated? (x2)

Answer 9

• INCISION AND DRAINAGE. Closure after drainage does not increase risk of recurrence, apart from anorectal abscesses
• ANTIBIOTICS: only recommended in addition to I&D in cases of severe abscesses. Flucloxacillin or dicloxacillin in S. aureus aetiology. MRSA can be treated with clindamycin and doxycycline. Antibiotics alone are ineffective due to encapsulation of abscess

Question 10

What are the complications of abscess?

Answer 10

Spreading and gangrene.

Question 11

What is the prognosis of abscesses?

Answer 11

Rarely fatal as they naturally drain through the skin. Brain abscesses have high mortality if left untreated, however.

Question 12

What are the indications for incision and drainage?

Answer 12

All abscesses.

Question 13

How is incision and drainage performed?

Answer 13

• Incision made parallel to skin tension lines to prevent scar tissue formation
• Abscess drained
• After drainage, the wound should be irrigated with normal saline
• Cover with dressing and tape

Question 14

What are the complications of incision and drainage? (x2)

Answer 14

Pain, extension of infection if inadequately drained