Tachypnea, Fever and Eosinophilia

Loffler syndrome is a helminth-associated eosinophilic pneumonitis which occurs when helminths transmigrate through the lung parenchyma and airways, provoking a marked eosinophil-mediated inflammatory response. The clinical picture is a constellation of transient pulmonary infiltrates on CXR, respiratory symptoms including cough and hypoxemia, and peripheral blood and pulmonary eosinophilia. Supportive care including supplemental oxygen and inhaled bronchodilators is helpful in acute management of Loffler-associated respiratory symptoms. Anthelmintic treatments may be used in particularly severe or refractory cases of Loffler syndrome, though the condition is generally self-limited. Strongyloides co-infection should be ruled out in patients who have risk factors for helminth exposure before the use of systemic steroids, particularly in otherwise immunosuppressed patients to avoid the potential risk of a disseminated hyperinfection syndrome. The same cautionary statement applies to monoclonal antibodies which are designed to inhibit IgE or eosinophils. Helminth infection should be considered in the differential diagnosis for asthma, eosinophilia, or elevated IgE, even in developed countries.