Pediculosis capitis: a hidden threat in tropical regions

Pediculosis capitis, caused by Pediculus humanus capitis, is a common ectoparasitic infestation primarily affecting school-aged children worldwide. It is transmitted through direct head-to-head contact and occasionally via fomites. Although not a vector for diseases, it causes significant psychosocial and economic burdens, including scalp itching, parental anxiety, absenteeism, and social stigma. The head louse life cycle includes egg, nymph, and adult stages, with the entire cycle completed in 21-30 days. Diagnosis is based on identifying live lice or viable eggs, often aided by wet combing or dermoscopy. Differential diagnoses include dandruff, hair casts, and fungal infections like piedra. Clinical features include pruritus, excoriations, secondary bacterial infections, and, in severe cases, conditions like plica polonica (a severely matted mass of hair stuck together with dirt, discharge, and infection, making combing impossible) or iron deficiency anemia. Treatment involves topical pediculicides, wet combing, and oral therapies for resistant cases, with no established global guidelines specific to pediculosis capitis. The condition disproportionately affects resource-poor communities, exacerbated by poverty, overcrowding, and limited access to treatment. Public health impacts include substantial healthcare costs and school absenteeism. Despite its prevalence, pediculosis capitis remains underrecognized as a neglected tropical disease, underscoring the need for integrated strategies to reduce its health and socioeconomic impact. This review highlights the epidemiology, pathophysiology, clinical presentation, diagnosis, management, and public health implications of pediculosis capitis, emphasizing the importance of awareness and effective interventions to mitigate its global burden.