Lone star ticks are well established throughout Maryland and rank among the most common ticks encountered in the state. They’re aggressive biters that actively pursue hosts (unlike deer ticks, which wait on vegetation), and they carry a unique set of health risks, including the ability to trigger a red meat allergy. Maryland falls squarely within the high-prevalence zone for both lone star tick populations and the allergic condition they cause.
How to Identify a Lone Star Tick
The adult female is the easiest to recognize: she has a single white dot, or “lone star,” centered on her dark brown back. Males lack that prominent spot but have scattered white streaks or spots along the edges of their bodies. Both sexes are roughly the size of a sesame seed before feeding and can swell to the size of a small grape when fully engorged.
Nymphs, the juvenile stage, are much harder to spot. They’re about the size of a poppy seed and lack the distinctive white markings, making them easy to mistake for a freckle or speck of dirt. Nymphs account for a large share of bites precisely because people don’t notice them. All life stages, including larvae, will bite humans.
When They’re Active in Maryland
Lone star ticks have a longer active season than many people expect. Adults that overwintered can become active as early as January or February, with their numbers peaking from March through May. Nymphs follow in two waves: overwintering nymphs are most active from April through June, while a second generation hatched that year peaks in July and August. Larvae tend to appear in late summer.
In practical terms, this means you can encounter lone star ticks in Maryland from late winter through early fall, with the highest risk window stretching from April to August. Wooded areas, grasslands, and the edges where forest meets lawn are their preferred habitat, and Maryland’s mix of suburban greenways, state parks, and Eastern Shore woodlands provides plenty of it.
Diseases Lone Star Ticks Carry
Lone star ticks transmit ehrlichiosis, a bacterial infection that causes fever, headache, muscle aches, and fatigue, typically within one to two weeks of a bite. Without treatment, ehrlichiosis can become serious, particularly in older adults or people with weakened immune systems.
They’re also associated with southern tick-associated rash illness, or STARI. The cause of STARI remains unknown. Researchers once suspected a spiral-shaped bacterium called Borrelia lonestari, but further studies didn’t support that theory. What is known: a red, expanding rash develops at the bite site, usually within seven days, growing to anywhere from 3 to 12 inches across. It sometimes clears in the center as it expands, creating a bull’s-eye pattern that looks a lot like the rash from Lyme disease. Fatigue, fever, headache, and joint pain often accompany it. Despite the visual similarity, STARI is not Lyme disease and is not caused by the same bacterium.
That distinction matters in Maryland, where both lone star ticks and blacklegged (deer) ticks are present. A bull’s-eye rash after a tick bite doesn’t automatically mean Lyme. Knowing which tick bit you helps your doctor choose the right approach.
Alpha-Gal Syndrome: The Red Meat Allergy
The most unusual health risk from lone star ticks is alpha-gal syndrome, an allergic condition that makes people react to red meat and other mammal-derived products. Alpha-gal is a sugar molecule naturally found in the bodies of most mammals, but not in humans. It’s also present in lone star tick saliva. When the tick feeds, it transfers alpha-gal into your bloodstream. Your immune system can flag that molecule as a threat, and from that point on, eating beef, pork, lamb, or other mammalian meat triggers an allergic response.
What makes alpha-gal syndrome tricky to recognize is the delay. Reactions typically don’t appear until two to six hours after eating, which is far slower than most food allergies. Symptoms range from hives and stomach cramps to severe anaphylaxis. Some people also react to dairy products or medications made with mammal-derived gelatin.
Maryland sits in one of the highest-prevalence regions for suspected alpha-gal cases in the country, according to CDC surveillance data from 2017 through 2022. The state is part of a nearly contiguous band stretching across the southern, midwestern, and mid-Atlantic United States where case rates are highest, closely mirroring the lone star tick’s established range.
How Alpha-Gal Syndrome Is Diagnosed
Diagnosis relies on a combination of your history and a blood test that checks for immune antibodies specific to the alpha-gal molecule. A positive blood test alone isn’t enough for a diagnosis, though. Many people in areas with lone star ticks test positive for these antibodies without ever developing symptoms. Your doctor will weigh the test result alongside your symptom pattern (especially the delayed timing), whether your reactions follow eating mammalian meat, and your history of tick bites or outdoor exposure. Skin-prick allergy tests for pork or beef may also be part of the workup.
Where in Maryland You’re Most Likely to Encounter Them
Lone star ticks thrive in deciduous forests with dense underbrush and are found across all of Maryland’s regions. The Eastern Shore, Southern Maryland, and central counties with mixed woodland and suburban development all report significant populations. Unlike deer ticks, which tend to cling to a blade of grass and wait, lone star ticks are host-seeking: they detect carbon dioxide and movement, then walk or even run toward you. This aggressive behavior means encounters happen in backyards and on paved trail edges, not just deep in the woods.
They’re also less particular about their hosts. Lone star ticks feed readily on deer, dogs, birds, and humans at every life stage, which helps sustain large populations in suburban areas where white-tailed deer are abundant.
How to Protect Yourself
Clothing treated with 0.5% permethrin is one of the most effective defenses. Permethrin kills ticks on contact and remains active through several washes. You can buy pre-treated clothing or apply the solution to pants, socks, and shoes yourself. For exposed skin, EPA-registered repellents containing DEET, picaridin, IR3535, or oil of lemon eucalyptus all work against ticks. (Oil of lemon eucalyptus products should not be used on children under three.)
After spending time outdoors in Maryland from spring through early fall, a full-body tick check is essential. Pay attention to the scalp, behind the ears, underarms, groin, and behind the knees. Showering within two hours of coming indoors helps wash off unattached ticks and gives you a chance to spot any that have latched on. Tossing clothes in a hot dryer for 10 minutes kills ticks that hitched a ride.
If you find an attached tick, use fine-tipped tweezers to grasp it as close to the skin as possible and pull straight up with steady, even pressure. Don’t twist, crush, or use nail polish or heat. Clean the bite area with rubbing alcohol or soap and water, and save the tick in a sealed bag or photograph it. Knowing the species helps if symptoms develop later.