When you have a sinus infection, the first thing you want is relief from your pain. If you’re like most people, you want your doctor to prescribe an antibiotic to speed that process. And the last thing you want is to be told to just wait it out.

But a study released Tuesday adds to the growing body of science suggesting that with some infections, including those of the sinuses, antibiotics aren’t the best course of treatment. Waiting it out may indeed be the best approach after all.

Overuse of antibiotics is considered an important and growing public health problem, as disease-causing bacteria continue to develop resistance to drugs we rely on to kill them. According to the new study, 1 in 5 prescriptions for antibiotics in the U.S. is for a sinus infection.

Researchers at Washington University School of Medicine in St. Louis report in the Feb. 15 issue of the Journal of the American Medical Association that in their study of 166 adults with sinus infections, those who were given the antibiotic amoxicillin didn’t feel better any faster than those who received a placebo. People in both groups experienced about the same amount of relief after three days.

“There is now a considerable body of evidence . . . that anti­biotics provide little if any benefit for patients with clinically diagnosed acute rhinosinusitis,” the researchers wrote. “Yet, antibiotic treatment for upper respiratory tract infections is often both expected by patients and prescribed by physicians.”

Jay Piccirillo, one of the study’s authors, said researchers chose the three-day mark because, while it’s well established in the scientific literature that most sinus infections resolve by 10 days with or without anti­biotics, they wanted to see if antibiotics hastened resolution. If their work had shown that antibiotics made people feel much better by Day 3, Piccirillo said, using the drugs might have been shown to be worthwhile.

By Day 7, the group receiving antibiotics was scoring better than the placebo group on reported symptoms such as headache, facial pain and nasal discharge. But Piccirillo said the gap between the two groups was not big enough to translate into a noticeable difference for most patients.

Patients in both groups were permitted to use a handful of over-the-counter medications to manage their pain, fever, cough and nasal congestion

Red lipsticks. (Mike Kemp for The Washington Post)

A new study from the Food and Drug Administration may have you thinking twice about your morning make-up routine. As The Post’s Dina ElBoghdady reports, four hundred types of lipstick were found to contain lead.

Here is a list of the 10 brands and shades that contain the most lead, according the FDA’s study. A full analysis of all 400 varieties is available here.

(Vahid Salemi - Associated Press) So maybe you don’t care much about air pollution’s effects on wildlife and such. But would you be more interested if you knew it might be tied to humans’ cognitive decline?

Research published Monday afternoon in the Archives of Internal Medicine suggests that chronic exposure to airborne particulate matter — small solid particles suspended in air — is associated with increased risk of cognitive impairment. The greater the exposure (in this study, over a four-year period), the study finds, the faster the cognitive decline.

That cognitive impairment can be a stepping stone toward dementia and to Alzheimer’s disease, which currently affects an estimated 5.1 million people in the United States.

The study paired data from the Nurses’ Health Study Cognitive Cohort (which features 14 years worth of data for more than 19,000 U.S. women ages 70 to 81, starting in 1988) with geographical information about pollution levels in participants’ locales. They found that exposure to both small and large particulates was associated with sizable cognitive losses. The authors say theirs is the first study to look at the effects of small as well as large particles in the ambient air.

Perhaps you’ve heard that kids today desperately need more sleep. Maybe you’ve even allowed yourself to get caught up in the panic over electronic devices’ stealing our children’s slumber, to the detriment of their mental and physical health and overall well-being.

A new study says “harrumph” to all that.

Research published Monday morning in the journal Pediatrics explains that the medical and public health communities have fretted over children’s sleep deprivation for generations. Everything from radio to reading has been blamed for keeping kids from getting the shut-eye they supposedly need: “In the early 1900s, artificial lighting, radio, reading, and the cinema were considered to be the causes of delayed bedtimes,” the authors write. “By the late 1990s, video games, television viewing, the Internet, and mobile telephones were largely held responsible for such delays.”

(Cliff DesPeaux - Reuters) A study published Thursday at bmj.com finds that people driving under the influence of cannabis (marijuana) are about twice as likely as unimpaired drivers to be involved in serious car crashes.

Researchers at Dalhousie University in Halifax, Nova Scotia analyzed existing studies to tease out the relationship between marijuana use and the risk of motor vehicle collision. After winnowing a field of 2,975 studies down to just nine that met their quality and design criteria, they found that driving after recent cannabis use was associated with a nearly doubled risk of being in a major collision compared to driving unimpaired. That relationship was particularly strong in the better designed studies and those that looked at fatal accidents.

The findings comport with those of a similar study published October in the journal Epidemiological Reviews.

The findings could be used to inform campaigns against driving while under the influence of drugs, the new study notes. An accompanying editorial suggests that random roadside drug testing may not be the best approach to discouraging marijuana-impaired driving. For one thing, the editorial notes, unlike blood-alcohol content, it’s not yet clear exactly what level of cannabis-related chemicals in the blood equates to impairment. Also, the editorial argues, the public’s awareness of those roadside drug stops isn’t high enough to make the prospect of being caught a sufficient deterrent to driving under the influence of marijuana.