How long does it take to get rid of head lice in a child?

One treatment: Generally, one treatment (shampoo, nit comb, hair accessory/brush cleaning and linen/bedding change) should be sufficient to rid one of lice. However, reoccurrence is common due to re-infection from improper cleaning of accessories, brushes or linens.

Depends on nits: Tx of lice requires accurate identification of nits & lice. A pediculicide is usually used- OTC like Nix or RID or prescription meds like lindane or malathion. Work carefully through hair & remove individual nits. Purchase a special lice nit comb to aid you. Check for nits & remove as seen over the next 7 to 10 days. If there are nits after 7 to 10 days – a 2nd pediculicide tx may be needed.

Not long if...: This depends on what method you use. Conventional treatment involves applying toxic pesticides so I advise alternatives. The safest and easiest treatment is heat; best to go to a treatment center so hope one is close to you- takes about an hour and your child will be lice-free: https://www.liceclinicsofamerica.com/clinics-near-you/