Strongyloidiasis is a parasitic disease caused by Strongyloides stercoralis (SS), a soil transmitted nematode of world wide distribution. This is a case report of a non-smoking farmer from Guyana who emigrated to the USA fourteen years ago. Over the course of 5 years she had recurrent hospitalization for AIHA, persistent wheezing, exertional dyspnea and eosinophilia.
Ms. SN is a eighty one year old female with past medical history of AIHA, B12 deficiency,aortic stenosis and chronic renal insufficiency. She was admitted in November 2004 with progressive wheezing, exertional dyspnea, cough productive of yellow sputum and fever for two weeks.She was diagnosed with B12 deficiency two and a half years ago. She also had recurrent hospitalizations for wheezing and exertional dyspnea over the same period. Work up revealed positive direct coombs test, raised Ig G, ANA of 1:320 and haptoglobin of <6. AIHA was diagnosed and corticosteroid was commnenced 4 months ago. Anemia persisted despite B12 supplimentation and corticosteroid treatement. She had multiple transfusion of packed red blood cells. Wheezing and exertional dyspnea progressively worsened until she became house bound. There was also a steady increase in eosinophil count. Continued administration of bronchodilators and corticosteroid provided no relief to these symptoms. On admission her blood pressure was 138/63 mmHg, heart rate was 66 beats/minutes, respiratory rate 24 breaths/minute, temperature 98.4 degrees Fahrenheit, oxygen saturation 93% on room air (RA) and peak flow 140 L/minute. Examination revealed an obese female with diffuse expiratory wheeze and a grade 2/6 systolic murmur over the precordium. Her hemoglobin was 6g/dL. She had a normal WBC with 35% eosinophils. Her blood urea nitrogen and creatinine were 29 and 1.8 respectively. Her arterial blood gas at RA was pH 7.33, PCO2 38, PO2 68. Chest x-ray showed enlarged cardiac silhouette. Echocardiography, electrocardiogram and ventilation perfusion lung scan were normal. She was transfused with two units of packed red blood cells and was treated with bronchodilators, corticosteroid and clarithromycin with little effect on wheezing and exertional dyspnea . Further work up revealed an elevated Ig E of 2600 (normal < 114), anti-filarial Ig G antibody titer of 1:4, positive stool SS larvae and moderate restrictive defect with DLCO of 52% on pumonary function test. A single dose of Ivermectin 200mcg/kg was administered. Within one week her dyspnea and wheezing resolved and over the ensuing three months, the eosinophilia and increased Ig E almost normalized. She no longer required bronchodilators, corticosteroid or B12 supplemetation.
Refractory wheezing, with restrictive or mixed ventilatory defect due to SS is an uncommon and under-diagnosed condition. In immunosuppresed populations, escalating to higher doses of corticosteroid in desperate attempt to control wheezing may lead to disastrous consequences. Positive filarial antibodies is not always diagnostic of tropical eosinophilia since cross reactivity of filarial and SS antibodies does occur. AIHA however is an exceedingly rare manifestation of SS. To the best of our knowledge the only published case of hemolytic anemia in association with SS was not documented as coombs positive. As in our patient it may be appropriate to treat strongyloides initially with follow up reassessment for additional filariasis treatment. Furthermore, Ivermectin in multiple doses has been shown to be effective in eradication of microfilaria as well.
SS infestation acquired years earlier, may manifest as hyperinfection syndrome decades later under the influence of immunosuppressive medications. SS infestation should be considered in the differential diagnosis of AIHA especially when associated with eosinophilia and refractory respiratory symptoms.
Alfred Ajise, No Financial Disclosure Information; No Product/Research Disclosure Information