Alpha-Gal Syndrome Diagnosis Time Drops 70-Fold, But Disparities Persist

A recent study found that the time from symptom onset to diagnosis of alpha-gal syndrome has significantly improved over time, dropping from an average of 5.3 years (2009 – 2011) to 28 days (2019).1

“In this cohort, the time between first symptom onset and confirmed [alpha-gal syndrome] diagnosis has shortened 70-fold over time,” wrote investigators, led by Caroline K. Maki, MPH, from the Rickettsial Zoonoses Branch, Division of Vector Borne Diseases, at the Centers for Disease Control and Prevention (CDC) in Atlanta Georgia.

Alpha-gal syndrome is an emerging tick-borne allergy to the galactose-a-1,3 galactose (alpha-gal) carbohydrate, a molecule found in mammalian meat, mammal-derived products, and certain pharmaceuticals. The distribution of alpha-gal syndrome resembles the distribution of the lone star tick, Amblyomma americanum. Patients with alpha-gal syndrome present symptoms 2 to 8 hours after consuming a product containing alpha-gal, and they may be life-threatening.

Approximately 450,000 individuals in the US have alpha-gal syndrome. Yet, a 2022 study reported that 42% of healthcare practitioners in the US have never heard of alpha-gal syndrome and 35% were not confident in their ability to diagnose and manage the condition.

Earlier this month, HCPLive spoke with one of the investigators of this study, Scott P. Commins, MD, PhD, from the department of medicine & pediatrics at the University of North Carolina, Chapel Hill, about how climate change has raised the prevalence of alpha-gal syndrome.2

“We think one of the biggest is the warmer winters have led to increased deer migration,” Commins said. “We find particularly in the US white-tailed deer now have an expanding geographic range. What that does is bring ticks into communities where they may not have been in the past, and that puts more people at risk for alpha-gal syndrome.”

This recent report assessed factors that may have impacted a patient’s ability to obtain a timely and accurate alpha-gal syndrome diagnosis.1 Maki and colleagues collected data from a case-control study conducted by the CDC’s Rickettsial Zoonoses Branch and the University of North Carolina at Chapel Hill (UNC) Allergy & Immunology Clinic.

The team analyzed a group of patients (69% North Carolina residents, 88% White participants, and 55% females) with alpha-gal syndrome who received care at an allergy clinic in North Carolina, specifically the University of North Carolina at Chapel Hill (2019; n = 18)), compared with an earlier cohort (2009 – 2011; n = 18) treated in the same allergy clinic. By comparing the new vs old cohort, investigators hoped to uncover the alpha-gal syndrome diagnosis trends over time.

The study ultimately found that the time from symptom onset to an alpha-gal syndrome diagnosis improved from an average of 5.3 years during 2009 – 2011 to 28 days in 2019, indicating a 70-fold reduction. This finding suggests an improvement in awareness and diagnostic capabilities for alpha-gal syndrome since 2011.

The study showcased a disparity when it comes to an alpha-gal syndrome diagnosis: patients with lower education levels experienced lower delays in diagnosis. On average, individuals with a high school education waited 4.4 years for a diagnosis, whereas those with a graduate degree waited 1.4 years.

“The delay in diagnosis for those with lower levels of education highlights a clear gap in access to care, even among this unique cohort with eventual access to a medical specialist and [alpha-gal syndrome] expert,” investigators wrote.

Investigators also found a significantly improved diagnosis time from 2015 to 2019, using data from a study examining the diagnosis time of 28 patients diagnosed with alpha-gal syndrome before late 2015. The analysis showed that from 2015 there has been a significant increase in the proportion of patients diagnosed with alpha-gal syndrome in less than a year and a significant decrease in those diagnosed in > 5 years. However, the mean diagnosis time of diagnoses > 1 year after symptom onset remained at 7.5 years.

“As we learn more about the growing population of patients with [alpha-gal syndrome] in the US, the disparities suggested by this study may become more apparent,” investigators wrote. “Health care practitioners should have a well-rounded awareness of the factors that may influence patients’ abilities to receive timely [alpha-gal syndrome] diagnoses to ensure the highest level of care and avoid undue physical, mental, and financial burden.”

References

1. Maki CK, Saunders EF, Taylor ML, Commins SP, Waller LA, Salzer JS. Time From Onset to Diagnosis of Alpha-Gal Syndrome. JAMA Netw Open. 2025;8(3):e2461729. doi:10.1001/jamanetworkopen.2024.61729

2. Derman, C. Climate Change’s Impact on Allergies, with Scott Commins, MD, PhD. HCPLive. March 2, 2025. https://www.hcplive.com/view/climate-change-s-impact-on-allergies-scott-commins-md-phd. Accessed March 24, 2025.