Head lice history and symptoms

History and Symptoms
Head lice are not known to transmit any disease and therefore are not considered a health hazard.

Head lice infestations can be asymptomatic, particularly with a first infestation or when an infestation is light. Itching ("pruritus") is the most common symptom of head lice infestation and is caused by an allergic reaction to louse bites. It may take 4-6 weeks for itching to appear the first time a person has head lice.

Other symptoms may include:
 * Tickling feeling of something moving in the hair.
 * Itching, caused by an allergic reaction to the bites.
 * Irritability.
 * Sores on the head caused by scratching. These sores can sometimes become infected.