Hemolytic Anemia as an Atypical Symptom of Katayama Syndrome

Schistosomiasis is an endemic parasitosis quite frequent in the Brazilian Northeast. Acute cases are often underdiagnosed given multiple more prevalent differential diagnoses with similar clinical presentation. A 25-year-old male patient, from a rural area in the interior of Bahia, presenting with prolonged fever, headache, myalgia, nausea, and vomiting for 1-month at admission. He evolved with cough, dark urine, epigastralgia, and jaundice, in addition to a loss of 10 kg since the onset of the clinical picture. On physical examination, he was jaundiced, febrile, with a painful abdomen, with mild hepatomegaly, without other findings. Laboratory tests showed leukocytosis associated with significant eosinophilia (30,000 leukocytes/mm 3 and 21,000 eosinophils/mm 3 ). In addition, there was elevated bilirubin, at the expense of indirect bilirubin, with normocytic and normochromic anemia, elevated LDH, and significant reticulocytosis. Direct Coombs negative, as well as viral serologies for hepatitis A, B, and C, HIV, HTLV negative; syphilis, toxoplasmosis, and CMV also negative. Chest tomography showed multiple nodules with soft-tissue density scattered throughout the lungs, bilaterally, small pericardial effusion, and abdominal CT with hepatomegaly with periportal edema. The patient reported having gone fishing in a pond close to his house with friends, about 1 month before the onset of symptoms. Stool parasitological examination confirmed the presence of Schistosoma mansoni eggs. Treatment with praziquantel was started, with a decrease in leukocytes/eosinophils, improvement of anemia and hemolysis tests, and total resolution of all symptoms. Non-immune hemolytic anemia is not a typical presentation of acute S. mansoni infection. It is known that the parasite has an intense influence on the inflammatory cascade in the pathophysiology of the disease, which could trigger some degree of anemia; however, the expected pattern would be anemia of inflammation and not hemolysis. Other factors may have influenced the emergence of hemolysis, such as medication use, but the improvement of the condition with the initiation of treatment for Katayama syndrome is noteworthy.