Types of Human Lice: Head, Body & Pubic Lice – Identification Guide

Three distinct species infest humans. Each prefers a specific body region and has unique characteristics:

Species	Common Name	Location	Size	Key Features
Pediculus humanus capitis	Head louse	Scalp hair	2–3 mm	Most common; lays nits on hair shafts; does not transmit disease
Pediculus humanus corporis	Body louse	Clothing seams; feeds on skin	2–3 mm	Lays eggs in clothing fibers; transmits epidemic typhus, trench fever, relapsing fever
Pthirus pubis	Pubic ("crab") louse	Pubic hair, sometimes eyebrows, eyelashes, chest, armpits	1–2 mm	Crab-shaped body; shorter, thicker legs; sexually transmitted; causes intense itching

Important Distinctions

• Head and body lice are same species (P. humanus) but different ecotypes—body lice evolved when humans wore clothing.
• Pubic lice are a separate genus (Pthirus).
• Body lice infestations signal poor hygiene/crowding; head lice affect all socioeconomic groups.
• Treatment differs: body lice require laundering/disposal of clothing + topical treatment; pubic lice need specific genital-area products.

If unsure which type, see a healthcare provider for identification and appropriate treatment.