What is the initial next step in managing a patient with trauma to their forearm and a suspected abscess, characterized by an erythematous (red), swollen, fluctuant lesion?

Initial Management of Post-Traumatic Forearm Abscess

The initial next step in management is incision and drainage (I&D), as this is the cornerstone of treatment for any fluctuant abscess and should be performed promptly. 1, 2, 3

Primary Treatment Approach

Incision and drainage must be performed first for this erythematous, swollen, fluctuant lesion, as these clinical findings definitively indicate abscess formation requiring surgical drainage. 1, 2

• The presence of fluctuance is the key clinical finding that mandates immediate I&D, regardless of abscess size or location. 1, 3
• Antibiotics alone are insufficient and ineffective without adequate source control through drainage. 1, 2, 4
• The drainage procedure should include thorough evacuation of pus and probing the cavity to break up any loculations. 1, 3

Role of Antibiotics (Secondary Consideration)

After performing I&D, the decision to add antibiotics depends on specific clinical criteria:

Antibiotics are NOT needed if: 1, 2

• Surrounding erythema is <5 cm from the abscess margin 1, 2
• Temperature is <38.5°C 1, 2, 4
• Heart rate is <100-110 beats/minute 1, 2, 4
• Patient is immunocompetent 2, 3

Antibiotics ARE indicated if: 1, 2, 4

• Temperature >38.5°C or <36°C 1, 4
• Heart rate >90-110 beats/minute 1, 2, 4
• Erythema extends >5 cm beyond the abscess 2, 4
• Signs of systemic inflammatory response syndrome (SIRS) are present 1, 4
• Patient is immunocompromised 2, 3
• Incomplete drainage was achieved 2

Wound Management After Drainage

• Simply covering the surgical site with a dry sterile dressing is usually the most effective approach. 1
• Packing may be considered for wounds >5 cm but causes more pain without clear benefit in healing. 1, 5
• Routine wound cultures are not necessary for typical cases but should be obtained if antibiotics will be used. 1, 2

Common Pitfalls to Avoid

• Never start with IV antibiotics alone without drainage, as this will fail to control the infection source. 1, 2, 4
• Do not delay drainage to obtain imaging in straightforward cases with obvious fluctuance on examination. 1
• Avoid needle aspiration as an alternative to I&D, which has only 25% success rate overall and <10% with MRSA. 1, 3
• Do not assume antibiotics are always needed—most simple abscesses after adequate drainage do not require them. 1, 5