Lice infestation causing severe anemia in a 4-year-old child

Head lice infestation, or pediculosis capitis, is common in the pediatric population. In North America, pediculosis capitis affects up to 40% of children.1 Management of this infection is often provided by primary care physicians and is well described in the literature,2 although despite its high prevalence, the effects of this infection if left untreated are not well understood. Lice survive on blood meals taken from their hosts, either human or animal. Host blood loss to an individual louse during feeding has been reported to be 0.008 to 0.7 mL/d in a study in elementary school children, and an average child has 20 to 30 live lice when infected.3 Theoretically, this blood loss could lead to anemia, especially in the setting of severe or chronic Pediculus humanus var capitis infestation. In fact, animal studies have demonstrated severe anemia attributed to a lice infestation in cattle.4,5

A search of MEDLINE and PubMed revealed only a handful of case reports describing the relationship between lice infestation and anemia. In humans, the literature is limited to 4 case reports totaling 5 patients with anemia associated with P humanus var capitis infestation.6–9 The first reported case was in a 61-year-old man with severe lice infestation and iron deficiency anemia, for which no other cause was found.7 In children, 3 cases have been reported, all with iron deficiency anemia and concurrent lice infestation.6,8 In all 3 cases, extensive investigations were done and no other cause of their iron deficiency anemia was found. Furthermore, following treatment of the lice infestation, all of the children’s serum hemoglobin levels were within normal range at the time of follow-up. Heart failure and other sequelae of severe ongoing anemia were not reported in any of these cases. Here we report a case of a 4-year-old child with a severe lice infestation and anemia with associated cardiac failure.