Abscess

Question 1

Define abscess

Answer 1

collection of pus within tissue

Question 2

What are the causes/risk factors of abscesses?

Answer 2

Abscesses can form anywhere in the body but are most common in or just under the skin and
teeth

Causes
• Bacteria e.g. Staphylococcus aureus
• Parasites
• Foreign objects

Risk Factors
• IVDU

Question 3

What are the signs and symptoms of abscesses?

Answer 3

• Erythematous
• Warm
• Tender
• Swollen
• Fluctuant

Question 4

What investigations are carried out for abscesses?

Answer 4

• FBC - leucocytosis and neutrophilia
• Aspiration - pus is acidic and is low in glucose.
- Culture may reveal the organism.
• Ultrasound - it can be useful in visualising an abscess.
• CT - this is indicated for deeper abscesses.
- IV contrast media are useful, since the vasodilation around an abscess enhances it, making it appear as a bright white ring around the abscess. This is known as ring enhancement.
• MRI - this is indicated for deeper abscesses, e.g. for Crohn’s disease.

Question 5

What is the management for abscesses?

Answer 5

• Some small skin abscesses may disappear by themselves
• Incision and Drainage
- Before doing this, check to see whether a foreign object is causing the abscess (e.g. needle fragments in IV drug users). This is done by X-rays and is important in IVDU.
- The abscess is cut open and drained of pus.
- It is important to ensure that all loculations are drained of the pus.
- The cavity is filled with gauze to prevent reformation of the abscess. This is then left to heal.
• Antibiotics: Can be used alongside incision and drainage

Question 6

What are the complications of abscesses?

Answer 6

• Spread may result in cellulitis (in skin) or bacteraemia with systemic sepsis.
• Recurrence
• Occasionally, antibiotics may penetrate and result in the formation of a sterile collection or antibioma.
• Pressure necrosis of surrounding tissue