DEAR DR. DONOHUE: Will you please tell me about head lice? My granddaughter has them and passed them to her mother. They are devastated, since they bathe every day and shampoo, too. How do you get them? How do you get rid of them? – K.H.

ANSWER: Nothing destroys the peace of a home more than discovering a child has head lice. They’re not evidence of poor hygiene or lax housekeeping. They usually don’t cause serious illnesses. They’re a nuisance. Outbreaks of lice happen every year when children go back to school.

Lice are transmitted from one head to another through direct contact or by sharing hats, combs, brushes or earphones.

They cause itching and, most often, nothing more. Lice eggs are glued to the shafts of hairs and look like oval pinheads. They’re called nits.

Permethrin can almost always eliminate lice. One brand name is Nix. Follow directions on its application. If over-the-counter permethrin doesn’t work, a stronger version, the 5 percent product, is available by prescription. Its brand name is Elimite. Other products also work.

Combing the hair with a fine-toothed comb dislodges the nits. Those combs are part of the kit that comes with the medicine.

Mothers don’t have to shift into overdrive to de-louse the home. A louse lives only a few days off the head. It’s only necessary to vacuum the carpets and furniture. Wash in hot water all clothing and bedding that has come in contact with the head, and dry them on high heat in the dryer. Soak combs and brushes for an hour in rubbing alcohol or Lysol, or wash them in hot water whose temperature is 130 F (55 C).

Lice do not live on pets. Pets don’t need any treatment.

DEAR DR. DONOHUE: There’s a new patch for Alzheimer’s disease. Isn’t a patch also planned for Parkinson’s disease? So far the basic Parkinson’s medicines are working for me, but I am looking forward to the patch. – D.A.

ANSWER: Skin patches are a method of medicine delivery that bypasses the stomach and provides a more constant level of medicine throughout the life of the patch. If your oral Parkinson’s medicines are doing the job for you, why do you want to switch?

The Parkinson’s skin patch is Neupro, and it’s available. It releases a medicine that substitutes for dopamine, the brain chemical that is at low levels in this illness.