Alpha-gal syndrome, or AGS, is a potentially serious allergic condition involving alpha-gal, a sugar molecule found in most mammals.
In the United States, Alpha-gal syndrome is most strongly associated with the bite of the lone star tick. Unlike more familiar food allergies, reactions may occur several hours after consuming beef, pork, lamb or other products containing alpha-gal, which can make the connection less obvious.
The CDC says that Alpha-gal syndrome can involve reactions to mammalian meat and other products containing alpha-gal and that the lone star tick is the tick species most often associated with the condition in the United States. People who suspect they are experiencing an allergic reaction should seek appropriate medical care and discuss possible Alpha-gal syndrome with a healthcare professional.
For Mosquito Shield of Greater San Antonio customers, Alpha-gal is another example of why preventing tick bites matters beyond the diseases homeowners may already recognize by name.
The lone star tick was historically associated most strongly with the southeastern and south-central United States, but its recognized range now extends considerably farther.
Current CDC surveillance describes the lone star tick as widely distributed across the Northeast, South and Midwest. The agency’s most recent distribution information includes counties with established populations documented through 2025. Importantly, the CDC also notes that a county not classified as having an established population should not be interpreted to mean lone star ticks are absent there.
This expanding geographic picture means Alpha-gal syndrome is no longer something homeowners in only a small portion of the Southeast should know about.
Lone star ticks are also aggressive human-biters. Adult females can often be recognized by the distinct white spot on their backs, although immature ticks are much smaller and can be considerably harder to notice.
There is no practical way for homeowners to control the geographic expansion of a tick species, but they can take steps to reduce tick encounters on their own property.
Ticks frequently occupy wooded edges, brush, leaf litter, tall vegetation and transition areas between maintained lawns and natural habitat. Keeping heavily used outdoor areas maintained, clearing unnecessary brush and leaf accumulation, checking people and pets after outdoor activity, and using appropriate personal tick-prevention measures can all help reduce exposure.
Mosquito Shield’s professional tick control services add another layer by targeting areas around residential properties where ticks are likely to live and come into contact with people and pets.
The changing range of the lone star tick also makes ongoing awareness important. Alpha-gal syndrome was once easy for many homeowners to dismiss as an unusual regional condition. As lone star ticks become established across a broader portion of the country, the number of people living in areas where encounters can occur continues to grow.
