Is it true that lice live under people's skin? - briefly
No, lice are external parasites that reside on hair shafts and the scalp surface, never burrowing beneath the skin. They attach to strands and feed by piercing the epidermis to draw blood.
Is it true that lice live under people's skin? - in detail
Lice are obligate ectoparasites that attach to the exterior of the human body. Head lice (Pediculus humanus capitis) and body lice (Pediculus humanus humanus) live on hair shafts or clothing fibers, while crab lice (Pthirus pubis) inhabit the coarse hair of the genital region. All three species keep their bodies exposed, using claws to grasp host hair and feeding by piercing the skin with a proboscis to draw blood.
The life cycle consists of egg (nit), nymph, and adult stages. Eggs are cemented to hair shafts with a protein secreted by the female. After 7‑10 days, nymphs emerge, molt three times over about two weeks, and become reproductive adults. Throughout development, the insects remain on the surface; they never penetrate the epidermis.
Burrowing beneath the skin is a characteristic of the mite Sarcoptes scabiei, which causes scabies. This distinction is often confused with lice because both produce itching and skin irritation. However, microscopic examination reveals that lice lack the anatomical adaptations required for tissue invasion.
Symptoms of lice infestation include localized itching, visible nits attached to hair, and occasional secondary bacterial infection from scratching. Diagnosis relies on direct visual identification of live insects or eggs. Effective treatment options include topical pediculicides (permethrin, pyrethrins) applied to the affected area, followed by thorough combing to remove nits. For body lice, laundering clothing at temperatures above 60 °C eliminates the parasites.
In summary, lice reside on the surface of hair or clothing, not within the skin layers. The misconception that they live under the skin likely arises from confusion with burrowing mites or from the intense itching they cause.