(TNS) Head lice, the scourge of day care centers and elementary schools, might have just become a bigger problem. A new strain of "super lice" has infested people in 25 states, potentially making it more difficult to get rid of the parasites. The Centers for Disease Control and Prevention reports there are up to 12 million cases of lice a year, mostly among children. But itching doesn't necessarily mean an active infestation, and neither does the sight of eggs. But if creepy crawlers are found, over-the-counter and prescription products can treat the social malady, said Dr. Bernard "Buddy" Cohen, a pediatric dermatologist at the Johns Hopkins Children's Center.

Q: How are super lice different from the usual bugs?

A: The "new" lice tend to have mutations that increase resistance to the over-the-counter pediculocides.

Q: How common is this new strain in children compared with the regular kind?

A: They are actually pretty common and may account for the majority of head lice around the country. It is still unclear if this makes a difference in terms of clinical response to treatment with these agents, so I still recommend a trial with over-the-counter products. If [there are] problems with response, and we are sure that the kids and families have been treated properly, I would consider using the newer [U.S. Food and Drug Administration] approved agents.

Q: I've heard that schools send home kids who are scratching, but does that necessarily mean lice? How is it diagnosed?

A: The definitive diagnosis requires identification of viable crawlers. The critters are pretty big and move quickly but should be easy to identify. If I can find real nits (eggs) on the scalp and the child has never been treated, I would also treat for infestation. The presence of nits after treatment and lack of live crawlers usually means that the infestation has been treated effectively. The nits can hang around for a long time, and the easily identifiable nits have usually already hatched or are dead and do not signify an active infestation. Therefore, no-nit policies at school make no sense as long as [children have] already [been] treated.

Q: Can you treat lice and super lice at home, and how do you know if it works? What do you do if over-the-counter options don't work?

A: Again, I would go with the over-the-counter products first and usually recommend at least two treatments spaced by seven to 10 days. If all close contacts have been treated properly and still have active crawlers, parents should discuss further treatment with their primary care providers and consider prescription agents.

Q: I've heard lice don't like leave-in hair products, but can you prevent lice?

A: Preventing lice really means teaching kids to avoid head-to-head contact at school and home, since spread requires close contact. The organisms are quick crawlers but don't fly. In some parts of the world, topical agents that might smother the breathing apparatus [like] dimethicone have been approved. However, there are no good randomized controlled trials to show that mayonnaise, Vaseline and similar products work to prevent infestation or treat active infestation.

No serious infectious diseases have been shown to be spread by head lice. It's just a social disaster and itchy.

———

©2015 The Baltimore Sun

Visit The Baltimore Sun at www.baltimoresun.com