Head lice, also known as nits, are a common problem among children ages 3-12 years old. However, many wonder at what age do people finally stop getting lice infestations. Here is an overview of when most people can expect to stop getting nits.
When Are Nits Most Common?
Nits are tiny insect parasites that live on the human scalp and feed on blood. The nit lifespan is around 30 days from egg to adult. They spread quickly from head to head through close physical contact or sharing personal items like hats, combs, pillows, and headphones.
School-aged children between 3-12 years old are by far the most commonly affected age group. According to the Centers for Disease Control and Prevention (CDC), children ages 3-11 years account for approximately 6-12 million lice infestations each year in the United States.
Preschoolers, teenagers, and adults can also get lice but much less frequently. Some reasons children get nits more often include:
- Close head-to-head contact at school, sports, camp, slumber parties
- Classroom learning materials, computer keyboards, sports helmets shared
- Coats, hats and other personal items stored close together on hooks/cubbies
- Some natural immunity develops with age
Peak Nit Infestation Ages
Nits are most prevalent in elementary school-aged children. According to studies, the peak ages for lice infestations are:
- 5-10 years old
- Girls tend to get nits more than boys
- Children with long hair are affected more
The highest number of cases generally occur in children ages 5-10 years when they are in close contact with other children at school. Frequent head-to-head contact while playing, hugging, etc spreads the parasite efficiently between children. Girls tend to have more infestations which may be due to hairstyle.
When Does Nit Incidence Decline?
The frequency of nit infestations starts to taper off around ages 10-12 years for several reasons:
- Pre-teen children tend to have less head-to-head contact
- Better hygiene and grooming make it harder for nits to thrive
- Possible development of some natural immunity to lice
As children get older, they tend to have less close physical contact while playing or studying. Improved bathing habits and hygiene make it harder for nits to survive on the scalp. Some research also indicates children may develop partial immunity after repeat exposures to lice.
Cases of lice in teens ages 13-17 are much lower than in elementary-aged children, but infestations can still occasionally occur. Slumber parties, sports activities, summer camp, and other close social interactions can put teens at risk of getting nits.
In the 18-24 year age range, cases of lice are relatively uncommon but not impossible. Some at-risk situations include:
- College dorm living
- Military barracks
- Young adult boarding school
When young adults live in close quarters such as college dorms, military barracks or boarding schools, it can facilitate lice spread. However, overall infestation rates are still low compared to grade school children.
Adults Over 25
By the time most people reach their mid-20s, occurrences of lice decrease significantly. While rare, adults can still get head lice in certain scenarios like:
- Being in close contact with an already infected child
- Trying on hats/helmets at stores
- Using infected person’s comb, brush, hat, pillow
If adults frequently hug, snuggle or lay heads together with infected children, they can catch lice. Adults may also get nits from trying on hats at stores or using contaminated hair accessories from others.
Cases of lice in the senior population over age 65 are very rare but can happen in situations like assisted living facilities. Dementia patients may be at increased risk due to behaviors like wandering into other resident’s rooms and bed areas.
Who Else is at Risk?
While children get nits much more frequently than adults, certain groups may be at increased risk including:
- Healthcare workers
- Parents or family members of infected children
- People who travel or live in crowded conditions
- Caretakers of people with lice
- Psychiatric facility residents
Nurses, doctors, and other healthcare providers can catch lice from infected patients. Shared hair accessories and close contact raise risk. Household members of children with lice also have increased risk of infestation.
While both adults and children can get head lice, it occurs most commonly in elementary school-aged children between 5-10 years old. Cases start to decline after age 12 as children have less physical contact and improved hygiene. By the mid-20s, infestations are rare but can still occasionally happen from contact with infected persons.
|Nit Infestation Risk
|5-10 years old
|13-17 years old
|Young adults 18-24 years old
|Adults over 25
|Very low risk
While annoying and uncomfortable, lice infestations are treatable and do not lead to serious medical problems. With proper treatment and prevention habits, children can grow up nit-free and leave this nuisance behind in childhood.