Post-Blister Wound Assessment: Concern for Secondary Infection

Case at a Glance

A 25-year-old healthy female presents with concerns about possible infection of a ruptured blister on her lateral foot that developed acute pain and erythema overnight.

Patient's Story

The patient developed a blister on the lateral aspect of her foot, which she believes spontaneously ruptured while ambulating the previous day. She awoke the following morning with new-onset sharp, tender pain in the affected area along with notable color changes. The patient described the area as appearing 'purplish-red' and feeling slightly warm to touch. She denied visible purulent discharge but was concerned about the possibility of secondary bacterial infection. She had been self-treating with topical antibiotic ointment and protective bandaging.

Initial Assessment

Physical examination revealed a ruptured blister site on the lateral foot with surrounding erythema and mild warmth. The patient reported acute onset of sharp, stabbing pain that worsened with weight-bearing. No obvious purulent drainage was observed at the time of assessment. The patient appeared otherwise well with no systemic symptoms.

The Diagnostic Journey

Given the acute onset of symptoms and visible inflammation, differential diagnosis included secondary bacterial infection, mechanical trauma/bruising from blister rupture, or normal inflammatory healing response. The patient was advised to monitor for progressive erythema, which would suggest advancing cellulitis requiring medical intervention.

Final Diagnosis

Post-blister rupture with localized inflammatory response, likely mechanical irritation rather than bacterial infection based on clinical presentation.

Treatment Plan

Conservative management with continued topical antibiotic application and protective dressing. Patient education provided regarding warning signs of infection including progressive erythema, increased warmth, purulent discharge, or systemic symptoms.

Outcome and Follow-up

Patient was advised to monitor the wound closely and seek medical attention if erythema continued to spread over subsequent days or if other signs of infection developed. The acute pain was attributed to tissue trauma from blister rupture and expected inflammatory response rather than infectious process.