Abstract
BACKGROUND Head lice is a common condition in school-age children caused by Pediculus humanus capitis. Although typically associated with scalp itching and discomfort, chronic or severe infestations can occasionally lead to more severe health consequences. This report describes a 12-year-old boy from Missouri, USA, presenting with iron deficiency anemia (IDA) and a severe head lice infestation. IDA is characterized by insufficient iron to meet the body's needs, typically due to blood loss, nutritional deficiencies, or malabsorption. While there is no established causative relationship between head lice and IDA, several case reports have suggested a co-occurrence, often in the absence of other identifiable causes. This raises the possibility that significant lice burden may contribute to or exacerbate IDA, particularly through blood loss from lice feeding on the host's scalp. CASE REPORT A 12-year-old boy presented to his pediatrician with fatigue, pallor, and weakness. Initial outpatient laboratory test data revealed a hemoglobin of 3.4 g/dL, necessitating urgent transportation to the emergency department (ED). Upon examination in the ED, a severe Pediculus humanus capitis infestation was incidentally discovered. Despite extensive inpatient workup, no other source of anemia was identified. The patient was treated with blood transfusions and topical pediculicides to address his anemia and head lice, respectively. Remarkably, his anemia and symptoms resolved without recurrence following these interventions. CONCLUSIONS Prolonged pediculosis capitis with high lice burden should be considered as a potential etiologic factor in patients with unexplained IDA and a negative anemia workup. Further research is warranted to explore the mechanisms linking these 2 conditions.