At a recent dinner party, Chattanooga resident Denise Murphy grabbed a shrimp from a tray. In the low light she didn't realize it was wrapped in bacon.
She woke up in the middle of the night with symptoms she typically experiences after eating red meat: an upset stomach, vomiting, hives, a sunburn-like rash and difficulty breathing.
"I realized right away what was happening," said Murphy, who was diagnosed with alpha-gal syndrome, a red meat allergy connected to lone star tick bites, in 2016. "It's more manageable now because I know what to do. In the beginning, I didn't know what was happening or what was wrong."
After her third trip to the emergency room with anaphylaxis -- a severe allergic reaction involving multiple organs -- with no known cause, Murphy's doctor referred her to an allergist who eventually diagnosed her with alpha-gal syndrome. That was in 2016, about a year after she started experiencing symptoms.
(READ MORE: Tennessee clinic finds majority of anaphylaxis due to tick bite meat allergy)
Dr. Michael Hollie, a physician with the Allergy and Asthma Group of Galen, said he has seen an increase in patients with alpha-gal syndrome over the past few years.
Short for Galactose-alpha-1,3-galactose, alpha-gal is a sugar found in mammal meat such as beef, pork, venison and lamb.
Alpha-gal syndrome has been connected to bites from lone star ticks, which are identified by a white spot resembling a star found on females' backs.
Symptoms can occur after eating red meat or exposure to other products containing alpha-gal and range from intermittent hives to swollen lips to anaphylaxis.
"I think there's not only an increase in cases but also an increase in awareness," Hollie said of alpha-gal syndrome, which was discovered in 2009.
(READ MORE: Bad bite: A tick can make you allergic to red meat)
When diagnosing alpha-gal syndrome, Hollie said he first looks at a patient's history of anaphylaxis and other similar symptoms such as hives, nausea, vomiting, diarrhea and breathing problems.
"The thing that distinguishes alpha-gal from other food allergies is that the symptoms are often delayed, sometimes two to six hours," he said, while most food allergies occur within the first few minutes after ingestion. "The classic scenario is somebody eats dinner in the evening which includes something with beef, lamb or pork, and then they wake up in the middle of the night at 1 or 2 a.m. with hives, itching, maybe nausea, vomiting."
Staff photo by Matt Hamilton / Denise Murphy walks through an overgrown area in Hixson on Wednesday, August 17, 2022.After looking at a patient's history, he would order a blood test that looks for allergic antibodies called immunoglobulin E, or IgE, against alpha-gal.
When someone is diagnosed with alpha-gal syndrome, Hollie said he prescribes an auto-injector epinephrine device, such as an EpiPen or AUVI-Q.
Murphy said she carries two EpiPens and allergy medication with her at all times and stays away from red meat and dairy products, both of which contain alpha-gal.
If she doesn't get any more lone star tick bites, Murphy's allergist said her alpha-gal allergy could eventually go away. Every six months her allergist tests the level of alpha-gal in her blood, which had been dropping gradually every year until her most recent visit, when tests revealed the level of alpha-gal in her blood had increased by five times since her previous test.
Murphy, a real estate agent who regularly walks undeveloped land, recalled getting three tick bites in the six months between the two tests.
"Every time I get bitten, my levels go back up," she said.
(READ MORE: Tick season has arrived in the South. How to avoid bites and what to watch out for.)
Karen Vail, an extension urban entomologist with the University of Tennessee Institute of Agriculture's Department of Entomology and Plant Pathology, said lone star ticks make up about 70% of the ticks she collected across East Tennessee for her research on managing ticks on school grounds.
Lone star ticks are also the most common ticks in Georgia, according to the Georgia Department of Public Health.
Various life stages of lone star ticks are active from February through October. They feed on humans at all stages of life, which distinguishes them from other types of ticks, Vail said.
If someone comes across lone star tick larvae, which can be found on vegetation from June through October, they could get dozens of bites at once, she said.
Vail recommends people wear insect repellent or clothes treated with repellent when outdoors in common tick habitats such as forests and fields.
She also suggests keeping lawns mowed, removing leaf litter, trimming shrubs, opening up the tree canopy as much as possible along the edges of the woods, and remove vegetation such as barberry or honeysuckle.
"Anything we can do to discourage wild animals from coming through our property may be helpful to reduce tick populations," she said.
Contact Emily Crisman at 423-757-6508 or ecrisman@timesfreepress.com.
How to identify lone star ticks:
> Females have a distinctive white spot on their backs and are about 3.1 millimeters long
> Males are red-brown with white/iridescence around the perimeter of the body and are about 2mm long
> Long palps (elongated, segmented appendages near the mouth)