Atypical hemolytic uremic syndrome in children

Hemolytic Uremic Syndrome (HUS) is one of a group of disorders grouped together as thrombotic microangiopathy (TMA) and characterized by the association of mechanical haemolytic anemia, peripheral thrombocytopenia, and failure of organs of variable severity (1). Atypical HUS with a different clinical presentation and evolution, the onset may be misleading and as typical HUS manifest as diarrhea. Atypical HUS represents only 10% of HUS cases in children (3). Although some causes can be identified, the etiology of atypical HUS often remains unknown (4). Atypical HUS occurs at all ages. The clinical presentation and evolution are different from those of postdiarrheal HUS. Prodromes such as vomiting, fever, and upper respiratory infection are inconsistent. Atypical HUS often has an insidious onset and evolves by pushing or progressively a single outfit. A neurological impairment can be observed. A high proportion of patients maintain more or less severe renal insufficiency and high blood pressure. Nevertheless, some children have a less severe form and a favorable prognosis (2). We report a rare pediatric case of atypical HUS without schizocytes on a blood smear with a picture of haemophagocytosis associated with an infant aged 23 months.