The Lone Star tick (Amblyomma americanum) is prevalent in the United States. It is recognized for its aggressive biting behavior and actively seeks out hosts, including humans. It readily feeds on various animals and often appears in large numbers, sometimes referred to as “seed ticks” in their larval stage.
Identifying the Amblyomma Tick and Its Habitat
The Lone Star tick (Amblyomma americanum) has distinct physical characteristics. Adult females are reddish-brown and easily recognized by a single, iridescent white or silvery spot in the center of their back. This spot can vary in color from white to cream or even bronze/gold. Adult females average 4-6 mm when unfed and can swell to 16 mm or larger when engorged.
Adult males, slightly smaller at 2-5 mm, lack the prominent white spot of the female. They typically display less distinct, scattered white or silvery streaks or patterns along the outer margins of their dark brown bodies. Compared to other common ticks like the blacklegged or deer tick (Ixodes scapularis), the Lone Star tick is generally larger, with adults around 1/3 inch long. Larval ticks have six legs, while nymphs and adults have eight.
The Lone Star tick’s habitat is primarily the eastern, southeastern, and south-central United States, though its geographic range has been expanding north and west. These ticks thrive in wooded areas with dense undergrowth, grassy fields, and along the edges of meadows and streams. Areas with common hosts like white-tailed deer and other wildlife are particularly favorable for their presence.
Diseases Transmitted by the Amblyomma Tick
The Lone Star tick is a vector for several infectious pathogens. One primary illness transmitted is Ehrlichiosis, caused by bacteria such as Ehrlichia chaffeensis and Ehrlichia ewingii. Symptoms of ehrlichiosis can include fever, chills, headaches, muscle aches, nausea, and vomiting.
Another significant disease associated with this tick is Tularemia, caused by the bacterium Francisella tularensis. The Lone Star tick also transmits Southern Tick-Associated Rash Illness (STARI), which can present with a red, expanding rash that may sometimes resemble the “bull’s-eye” rash seen in some Lyme disease cases. The tick also transmits viruses like Heartland virus and Bourbon virus. Heartland virus can cause illness, and Bourbon virus is a newly identified virus.
The Alpha-Gal Red Meat Allergy
Beyond infectious diseases, the Lone Star tick bite can uniquely trigger alpha-gal syndrome (AGS), an allergy to a sugar molecule called alpha-gal. This sugar is found in most mammals, including beef, pork, and lamb, but generally not in poultry or fish. The mechanism behind AGS involves a substance in the tick’s saliva that, when introduced into a human’s bloodstream during a bite, sensitizes the person’s immune system to alpha-gal.
When an individual with this sensitization subsequently consumes mammalian meat, their immune system recognizes the alpha-gal as a foreign substance, leading to an allergic reaction. A distinguishing feature of AGS symptoms is their delayed onset, often occurring 3 to 6 hours after consuming red meat. Symptoms can range from hives and swelling to gastrointestinal upset, and in severe cases, anaphylaxis, a life-threatening allergic reaction. This delayed reaction makes alpha-gal syndrome challenging to diagnose without awareness of its association with tick bites.
Prevention and Safe Removal
To minimize Lone Star tick bites, preventive measures are recommended when spending time outdoors, especially in wooded or grassy areas where these ticks thrive. Using EPA-registered insect repellents containing active ingredients like DEET or picaridin on exposed skin can deter ticks. Treating clothing and gear with permethrin offers an added layer of protection, as permethrin can kill ticks on contact.
Wearing protective clothing, such as long-sleeved shirts and pants, and tucking pant legs into socks, can create physical barriers against ticks. Staying on marked trails and avoiding dense vegetation can also reduce exposure to tick habitats. After returning indoors, perform thorough tick checks on oneself, children, and pets, paying close attention to areas like the hairline, ears, armpits, groin, and behind the knees.
If a tick is found attached, prompt removal is important. Use fine-tipped tweezers to grasp the tick as close to the skin’s surface as possible. Pull upward with steady, even pressure, avoiding twisting or jerking movements that could cause the mouthparts to break off and remain in the skin. After removing the tick, clean the bite area thoroughly with rubbing alcohol or soap and water. Avoid folk remedies such as applying nail polish, heat, or petroleum jelly, as these methods are not effective and may cause the tick to release more saliva or pathogens into the bite wound.