Allergy season is upon us once more, and for many allergy sufferers, that means it’s time to pull two crucial items to the front of the medicine cabinet: 24-hour non-drowsy loratadine, and a neti pot—a teapot-like device used to flush the nasal passages with saline in order to clear allergens and soothe sinus pressure. (It can be seen in action in this very popular gif.) The constant mockery of my loved ones doesn’t prevent me from using a neti pot to ease my congestion. It’s too effective to give up for the sake of pride. But I have also used my neti pot with considerable apprehension since 2011.
That year, a 20-year-old man from Louisiana died of encephalitis caused by Naegleria fowleri, an amoeba commonly found in lakes and rivers in the American South—but which rarely causes infection. More unusual still was the fact that the young man hadn’t had been swimming in freshwater lakes or rivers anytime recently. Then, a few months later, a 51-year-old Louisiana woman also died of encephalitis—primary amebic meningoencephalitis (PAM) to be exact, which is the condition caused when Naegleria fowleri infects the brain. Shortly before she passed away, her doctor learned that while she hadn’t had been swimming in freshwater either, she had recently used a neti pot. Researchers later learned that the other victim had also used a neti pot, and subsequent testing found Naegleria fowleri in both patients’ brain tissue as well as the tap water in their homes. Using a neti pot had allowed the amoeba to reach their brains.
It didn’t take long for these two unusual—and deeply tragic—incidents to become a widespread and frequently alarmist cautionary tale. Media outlets ran stories like “Brain-Eating Amoebas Might Be Hiding in Your Neti Pot,” often including incomplete and misleading information about said amoeba. Good Housekeeping implied that PAM can be caused merely by swimming in lakes and rivers, which isn’t really the case, says Salvatore Iaquinta, an otolaryngologist at Kaiser Permanente. “If you go swimming in those lakes and you swallow the water, nothing's going to happen. Your stomach will kill the amoeba,” he says. Hence why we don’t hear much about the Naegleria fowleri risk—if you’re showering in water that contains the amoeba, or drinking it from the tap, it won’t be a problem. “It’s getting the water flushed up high in the top of the nasal passage [that’s the problem.]” One way this might happen is if you dive or cannonball into a lake where this amoeba is present; another way is if you flush water containing the amoeba up your nose using a neti pot.
“For some reason, we don't know why, but [Naegleria fowleri] is attracted to following the pathways of the little nerves that come out of your brain for your sense of smell,” Iaquinta tells me. “It follows those nerves into the brain, and that’s how it causes its damage.” Thus, it isn’t the neti pot itself which poses a risk, but the mechanism it enables. If you fill it with boiled water as directed, your neti pot shouldn’t contain Naegleria fowleri, or any other microorganism.*
Iaquinta says that many of the patients he sees don’t realize that the salt packets provided with most neti pots (or sold alongside them in drugstores) are a mandatory part of good neti pot practice. “Some people don't know. I've had plenty of patients come in who’ve rinsed with shower water or regular water,” says Iaquinta. “You need to have the salinity—plain water irritates your nose. Some people use table salt, and table salt usually has iodine in it, which is also irritating.” It’s not just about avoiding irritation, either—achieving the proper salinity protects you from microorganisms that can’t survive in saltwater, like Naegleria fowleri. “It's a freshwater thing,” says Iaquinta.
Because I’d like to expend the least effort possible, I ask Iaquinta if, since saline packets kill bacteria, it’s still important to boil or distill tap water before using it to flush my nose. (It’s not that big of a deal, I know—it’s just annoying waiting for it to cool off!) Like any good doctor, he refuses to let us slackers off the hook. “Right, but it’s safer to say to use boiled or distilled water, because that kills everything.” Saline packets are better than nothing, but using saline packets and boiled or distilled water is best.
Iaquinta stresses that the transmission of brain-eating amoeba by neti pot is exceedingly rare, and can be avoided by using sanitized water and saline packets as directed. And though it may look goofy, he’s a big proponent. “You're constantly being exposed to what you're allergic to, so if you're rinsing away whatever it is you're allergic to, you're going to reduce your symptoms,” he says. “That's the real benefit of the nasal saline, is constantly washing those allergens away.” It’s also cheaper than most over the counter anti-allergy medicines. Adds Iaquinta: “It’s just nasal saline. I tell people to start with the easy, natural thing rather than telling people to take medicine everyday.” Just make sure you follow the directions, and hang in there until the first frost.
* This article originally mischaracterized Naegleria fowleri as a bacterium. It is a eukaryote. We regret the error.