April 10 (HealthDay News) -- A prescription medication, benzyl alcohol lotion 5 percent, has been approved by the U.S. Food and Drug Administration to treat head lice.

More than 1 million children annually are affected by head lice (pediculosis capitis), the agency said in a news release. The newly approved medication was established as safe and effective in two studies of 628 people. After two, 10-minute treatments given a week apart, more than 75 percent of trial participants treated with the lotion were lice free.

The most common side effects of the treatment were irritations of the skin, scalp and eyes, and application site numbness.

The product should never be used in infants younger than six months, as they could suffer respiratory, heart or brain problems that result in seizure, coma or death, the FDA said.

The treatment is distributed by Sciele Pharma Inc.