What are the clinical features of strongyloidiasis?

Clinical Features of Strongyloidiasis

Larva currens is the most common clinical presentation of strongyloidiasis, characterized by an itchy, linear, urticarial rash that moves rapidly around the trunk, upper legs, and buttocks, though many patients remain asymptomatic or present with non-specific gastrointestinal symptoms. 1

Cutaneous Manifestations

• Larva currens represents the hallmark dermatologic finding—an intensely pruritic, serpiginous, urticarial rash that migrates several millimeters per second, typically affecting the trunk, buttocks, and upper thighs 1
• Initial skin penetration by larvae may cause a pruritic papular rash at the site of entry 1
• Urticarial rashes can occur during acute infection phases 1

Gastrointestinal Presentations

• Non-specific symptoms including diarrhea, abdominal pain, and abdominal bloating are common but easily overlooked 1
• Chronic diarrhea with weight loss may develop in persistent infections 2
• Nausea and vomiting can occur, occasionally severe enough to mimic gastric outlet obstruction 3
• Epigastric discomfort and early satiety have been reported 3

Pulmonary Manifestations (Löeffler's Syndrome)

• Acute respiratory symptoms develop during larval migration through the lungs, presenting with dry cough, wheeze, and breathlessness 1
• This occurs days to weeks after initial infection and represents an immunologic response to migrating larvae 1
• Chest radiographs may show transient migratory pulmonary infiltrates 4
• Hemoptysis is rare but possible 4

Timing of Clinical Presentations

• Larva currens and Löeffler's syndrome: Days to weeks after exposure 1
• Gastrointestinal symptoms: Typically 2 weeks or more after infection 1
• Prepatent period (time until larvae appear in stool): 4 weeks 1

Hyperinfection Syndrome (Life-Threatening Complication)

This represents the most critical clinical scenario and occurs exclusively in immunocompromised patients:

• Results from unchecked autoinfection cycles in patients with defective granulocyte function 1
• Key risk factors include corticosteroid therapy, chemotherapy, malignancy, HTLV-1 infection, HIV/AIDS, organ transplantation, and chronic renal failure 1, 5, 6, 2
• Manifests as paralytic ileus, gastrointestinal bleeding, and gram-negative bacteremia from intestinal translocation 1, 6
• Can progress to pneumonia, sepsis, meningitis, and multi-organ failure 7
• Mortality rate reaches 60-87% in hyperinfection and disseminated disease 6, 5

Asymptomatic Infection

• Many immunocompetent individuals remain completely asymptomatic despite chronic infection 1, 5
• Eosinophilia may be the only laboratory finding in asymptomatic carriers 1
• This silent carriage poses significant risk if immunosuppression occurs years later 5, 6

Associated Laboratory Findings

• Eosinophilia is common in chronic uncomplicated strongyloidiasis 1
• Eosinophilia may be absent during hyperinfection syndrome due to overwhelming immunosuppression 1
• Mild anemia can occur with chronic infection 3

Critical Clinical Pitfall

The most dangerous scenario occurs when corticosteroids are empirically prescribed to treat symptoms (such as respiratory complaints or abdominal pain) that are actually caused by unrecognized strongyloidiasis—this can precipitate fatal hyperinfection syndrome. 6 Steroids represented the main trigger in 67% of hyperinfection cases, often administered to treat the very symptoms caused by the undiagnosed parasitic infection 6. This underscores the absolute necessity of screening for Strongyloides before initiating any immunosuppressive therapy in at-risk populations 7, 4, 8.