Etiology, Pathogenesis, and Diagnostic Features of Pediculosis

Introduction

Pediculosis, commonly known as lice infestation, is caused by parasitic insects of the Pediculidae family. It primarily affects the scalp, body, and pubic region, leading to itching and irritation.

Etiology of Pediculosis

Causes

The primary cause of pediculosis is the infestation of lice species: Pediculus humanus capitis (head lice), Pediculus humanus corporis (body lice), and Pthirus pubis (pubic lice). These insects feed on human blood and reproduce rapidly.

Risk Factors

• Close human contact, especially in crowded environments.
• Poor hygiene and limited access to clean clothing.
• Sharing personal items like combs, hats, or clothing.

Transmission Methods

Lice are transmitted through direct person-to-person contact or indirectly via infested objects. Body lice can also spread through contaminated clothing and bedding.

Pathogenesis

Lice infest the host by attaching to hair shafts or clothing fibers. Their bites cause local irritation and hypersensitivity reactions, leading to pruritus (itching) and secondary bacterial infections due to scratching.

Diagnostic Features

• Presence of live lice and nits (eggs) on the scalp, clothing, or pubic hair.
• Intense itching and erythematous papules at infestation sites.
• Excoriations and secondary infections from scratching.

Treatment and Prevention

Management includes topical pediculicides like permethrin, mechanical removal using fine-toothed combs, and improving personal hygiene. Preventive measures involve avoiding head-to-head contact and regularly washing clothing and bedding.