Antigens in an hydatid cyst can be the trigger for anaphylaxis during surgery.
Risk factors for echinococcosis include:
(1) living in or travel to an endemic region
(2) high risk occupation (sheep farmer, hunter, etc)
Triggers for anaphylaxis may include:
(1) trauma (including motor vehicle accident)
(2) surgery or aspiration of a suspected hydatid cyst
(3) surgery or aspiration of any other cyst (usually hepatic but can be elsewhere)
Clinical presentation:
(1) sudden hemodynamic collapse
(2) sudden increase in airway pressures (associated with bronchospasm)
(3) generalized erythema
Blood testing will be positive for histamine and tryptase.
Exclusion of alternative diagnoses:
(1) carcinoid syndrome
(2) tension pneumothorax
(3) acute myocardial infarction
(4) other causes of anaphylaxis
(5) hypovolemic shock
