How do you drain a boil?

How to Drain a Boil

Incision and drainage is the recommended primary treatment for large furuncles (boils) and all carbuncles. 1

Understanding Boils

• Boils (furuncles) are infections of hair follicles, usually caused by Staphylococcus aureus, where infection extends through the dermis into subcutaneous tissue, forming a small abscess 1
• Carbuncles develop when infection involves several adjacent follicles, producing a coalescent inflammatory mass with pus draining from multiple follicular orifices 1

Management Approach

Small Boils

• For small furuncles, application of moist heat is satisfactory and may promote spontaneous drainage 1
• Apply warm compresses to the area for 10-15 minutes, several times a day to help bring the boil to a head 1
• This approach allows the boil to drain naturally without surgical intervention 1

Large Boils and Carbuncles

• Incision and drainage is the definitive treatment for large boils and all carbuncles 1, 2

• The procedure involves:

  1. Making an incision to access the abscess 1
  2. Thorough evacuation of all pus 1
  3. Probing the cavity to break up loculations (pockets of pus) 1
  4. Covering the surgical site with a dry dressing 1

• Simple covering of the incision site with sterile gauze is usually sufficient - packing the wound with gauze has been found to cause more pain without improving healing 1

After Drainage Care

• Keep the area clean and dry 1
• Change dressing as needed when soiled 1
• Continue warm compresses to promote continued drainage 1
• Monitor for signs of spreading infection such as increasing redness, warmth, or fever 2

When to Consider Antibiotics

Antibiotics are generally not required for simple boils that have been adequately drained, but should be considered in the following situations:

• Presence of systemic inflammatory response syndrome (fever >38°C, rapid breathing, rapid heart rate) 1
• Markedly impaired host defenses 1
• Extensive surrounding cellulitis 1
• Severe systemic manifestations of infection 1, 2

Prevention of Recurrent Boils

• Daily chlorhexidine washes to reduce bacterial colonization 1
• Daily decontamination of personal items such as towels, sheets, and clothes 1
• Thorough laundering of clothing, towels, and bed wear 1
• Separate use of towels and washcloths 1
• Consider evaluation for underlying conditions if boils are recurrent 3

Risk Factors for Recurrent Boils

• Obesity (RR 1.3) 3
• Diabetes (RR 1.3) 3
• Smoking (RR 1.3) 3
• Age <30 years (RR 1.2) 3
• Prior antibiotic use (RR 1.4) 3

Common Pitfalls to Avoid

• Ultrasonographically guided needle aspiration has been shown to be successful in only 25% of cases overall and <10% with MRSA infections, and is therefore not recommended 1
• Overuse of antibiotics for uncomplicated boils that could be managed with incision and drainage alone 1, 2
• Inadequate drainage leading to recurrence or persistent infection 1
• Failure to break up loculations during drainage procedure 1