Clinical Manifestations of Loeffler's Syndrome
Core Presentation
Loeffler's syndrome presents with fever, dry cough, wheeze, urticaria, and migratory pulmonary infiltrates on chest radiograph, typically occurring 1-2 weeks after helminth infection during larval lung migration. 1
Respiratory Symptoms
- Dry cough is the predominant respiratory complaint 1, 2
- Wheeze and dyspnea occur due to bronchial irritation from migrating larvae 1, 2
- Hemoptysis is rare but documented 1, 3
- Shortness of breath with reduced exercise tolerance may develop 2
Systemic Manifestations
- Low-grade fever is common and may persist for days to weeks 1, 2
- Urticaria (hives/skin rash) results from allergic response to larvae 1, 4
- Most patients are mildly ill or asymptomatic despite radiographic findings 2, 5
Laboratory Findings
- Peripheral blood eosinophilia is the hallmark finding, reaching up to 70% 1, 6, 3
- Elevated total IgE levels support the diagnosis 7
- Elevated C-reactive protein may be present 3
- Stool examination is often negative during the prepatent period when symptoms occur 1
Radiographic Features
- Migratory pulmonary infiltrates that change location on serial imaging 1, 4, 2
- Abnormal chest radiography occurs in 95% of patients 3
- Unilateral or bilateral patchy consolidations in lower zones are typical 7, 3
- Pleural effusion may develop in complicated cases 3
Timing and Duration
- Symptoms occur 1-2 weeks post-infection during the prepatent period 1
- Self-limited course lasting days to months with spontaneous resolution 2, 5
- Recovery typically occurs within 40 days even without specific treatment 6
Common Pitfalls
- Mimics bacterial community-acquired pneumonia, leading to unnecessary antibiotic use 7
- Diagnosis requires high clinical suspicion in patients from endemic areas with eosinophilia 7
- Stool examination may be falsely negative during symptomatic phase 1
- Must differentiate from Churg-Strauss syndrome, which includes asthma history 2