[A mortal cause of syncope].

Area of Science:

• Allergy and Immunology
• Emergency Medicine
• Parasitology

Background:

• Anaphylaxis is a life-threatening systemic reaction caused by mast cell mediator release.
• Diagnosis can be challenging due to nonspecific symptoms overlapping with other conditions, leading to underdiagnosis.
• A high index of clinical suspicion is crucial for prompt recognition and management.

Observation:

• A young woman presented with syncope and refractory hypotension in a primary care setting.
• Despite the absence of typical skin manifestations, anaphylaxis was suspected due to persistent low blood pressure.
• Elevated serum tryptase levels in the Emergency Department supported the anaphylaxis diagnosis.

Findings:

• The patient's presentation was ultimately attributed to the rupture of hydatid cysts, a rare cause of anaphylaxis.
• Abdominal ultrasound and CT scans confirmed the presence of hydatid cysts.
• This case underscores the importance of considering unusual triggers for anaphylaxis.

Implications:

• Ruptured hydatid cysts should be considered in the differential diagnosis of anaphylaxis, particularly in endemic areas.
• This case highlights the importance of advanced imaging in diagnosing rare causes of anaphylaxis.
• Improved diagnostic strategies are needed to address the underdiagnosis of anaphylaxis.