, but doctors in one city are warning of another schoolhouse health risk among kids in close quarters: "super lice."
Schools in Pittsburgh, Pa. have seen an uptick in so-called super lice, but unlike the traditional pesky critters that find their ways in kids' hair, these lice don't respond to typical treatments.
"When you look in the literature there's more and more reports of resistance among head lice," Dr. Robin Gehris, a pediatric dermatologist at Children's Hospital of Pittsburgh, told CBS station KDFA in Pittsburgh.
A head louse is a parasitic insect found on people's hair, eyebrows and eyelashes, where they feed off blood from the scalp several times a day.
Lice also lay eggs called nits that attach to the hair shaft and hatch within nine days.
Between 6 million to 12 million infestations occur each year in U.S. kids ages 3 to 11 years, the Centers for Disease Control and Prevention says.
Gehris pointed out that lice can be easily treated with over-the-counter medicated shampoos and sprays containing an active ingredient of an insecticide called permethrin. Unfortunately, it doesn't always do the trick, as she sees firsthand in about 10 children a month.
"When you look in the literature there's more and more reports of resistance among head lice," she said.
In that case, she prescribes a stronger, prescription medication, but some of those have stronger odors or can be flammable, so they are not recommended as the first treatment parents turn to.
Prescription medications for head lice include malathion, lindane and benzyl alcohol lotion, according to the Mayo Clinic. Head lice is not a sign of bad hygiene or living somewhere unclean, the Clinic emphasized.
Symptoms of a child with head lice include feeling tickling, itching, irritability, difficulty sleeping -- since the bugs are most active at dark -- and developing sores.
To avoid head lice to begin with, health officials urge parents and caretakers to try and limit their child's direct head to head contact with other kids, which could occur during play at home or school. Sharing clothes with someone infected may also spread head lice, though that route of transmission is far less common than direct hair-to-hair contact.
If you want to avoid insecticide medication entirely, the Mayo Clinic recommends using fine-toothed or nit comb every three to four days to remove the lice from wet hair over a two-week period.
Parents can also try natural remedies like mayonnaise, olive oil, vinegar or heavy moisturizers to suffocate or dislodge the lice, said Gehris, but if that doesn't work, they can turn to over-the-counter products or a trip to the doctor's.
"Many of the over-the-counter products are very effective at treating lice on the very first pass," she said.