What is the recommended treatment for pulmonary Candida infection?

Treatment of Pulmonary Candida Infection

Pulmonary Candida infection rarely occurs and should not be treated with antifungal therapy, as growth of Candida from respiratory secretions typically represents colonization rather than invasive disease. 1

Understanding Pulmonary Candida: Colonization vs. Infection

Candida isolated from respiratory secretions presents a common clinical dilemma. The guidelines provide clear direction on this issue:

• Candida pneumonia and lung abscess are extremely uncommon 1
• Respiratory colonization with Candida is very common, especially in critically ill patients on mechanical ventilation 1
• Multiple prospective and retrospective studies, including autopsy studies, consistently demonstrate the poor predictive value of Candida growth from respiratory secretions 1

Key Diagnostic Considerations

A true diagnosis of pulmonary Candida infection requires:

• Histopathological confirmation 1
• Clinical evidence of invasive disease beyond just positive cultures 1

The 2016 IDSA guidelines strongly recommend (with moderate-quality evidence) that growth of Candida from respiratory secretions usually indicates colonization and rarely requires antifungal therapy 1.

Special Circumstances

There are rare exceptions where pulmonary Candida infection may occur:

1. Hematogenous dissemination: Candida may produce lesions in the lungs as part of disseminated candidiasis 1
2. Severely immunosuppressed patients: In these cases, isolation of Candida from respiratory samples should trigger a search for evidence of invasive candidiasis 1

Clinical Approach

When Candida is isolated from respiratory secretions:

1. Do not initiate antifungal therapy based on respiratory cultures alone 1
2. Look for evidence of disseminated candidiasis if the patient has risk factors or clinical signs of invasive disease
3. Consider histopathologic confirmation if true pulmonary Candida infection is strongly suspected

Common Pitfalls to Avoid

1. Overtreatment: Initiating antifungal therapy based solely on positive respiratory cultures is a common mistake 1
2. Misinterpretation: A positive culture from respiratory secretions is frequently misused as an indication to start antifungal therapy in febrile patients without other evidence of invasive disease 1
3. Ignoring the evidence: Multiple studies have shown that Candida in respiratory secretions rarely represents true infection 1

Recent Observations

Some studies suggest that Candida airway colonization may be associated with:

• Development of bacterial colonization and pneumonia
• Worse clinical outcomes and higher mortality

However, it's not clear if this represents a causal relationship or if Candida colonization is simply a marker of disease severity 1.

In conclusion, the most recent and highest quality evidence strongly recommends against treating Candida isolated from respiratory secretions with antifungal therapy unless there is histopathologic evidence of invasive disease.