How is pathogenesis of pediculosis?

• Female adult lice live 30 days and lay 5-10 eggs (nits) per day at the base of the hair where it meets the scalp • Eggs hatch in 8-12 days • Live eggs remain close to the scalp to maintain warmth and moisture but as the hair grows, the nits move off the scalp with the hair • Because hair grows at a rate of ~ 1 cm per month, the duration of infestation can be estimated by the distance of the nit from the scalp • The adult head lice is 2-3 mm in length and has six legs • The presence of live adult lice, immature nymphs, and/or viable eggs indicate active infestation • Lice typically survive 1-2 days away from the scalp. Eggs may survive up to 10 days away from the scalp