Head lice presenting with isolated severe eosinophilia in a child

Eosinophilia is frequent in pediatrics and concerns regarding its etiology are often raised. Pediculosis capitis is a common ectoparasitic disease in children but is not traditionally associated with changes in laboratory parameters. We present the case of a healthy, 9-year-old girl who presented with abdominal pain and a history of loose stools (2-3) in the preceding week. Laboratory investigations showed leukocytosis with significant eosinophilia. A thorough investigation concerning the most common causes of eosinophilia was negative. Detailed physical examination and history revealed a persistent scalp infestation with head lice. Successful pediculosis management coincided with the gradual resolution of eosinophilia without recurrence until the most recent follow-up visit twelve months later. The presented case indicates a possible association between eosinophilia and pediculosis capitis, which was not previously displayed, but also highlights the importance of detailed history and clinical examination. Research focusing on the systematic effects of pediculosis capitis in children could clarify whether it can represent a frank cause of eosinophilia. HIPPOKRATIA 2023, 27 (2):112-114.