Clinical Testing and Diagnosis for Alpha-gal Syndrome

Key points

  • Alpha-gal syndrome (AGS) is diagnosed using a detailed patient history, physical examination, and a blood test.
  • Allergy skin testing may also be used to diagnose AGS.
  • AGS is not a nationally notifiable condition, but CDC encourages jurisdictions to share information on AGS.
Tray with multiple cuts of meat

Recommended tests

The main diagnostic test for AGS is a blood test looking for immunoglobulin-E antibodies specific to alpha-gal (alpha-gal sIgE).

  • Tests for alpha-gal sIgE antibodies are available at several large commercial laboratories.
  • Tests also may be available at some academic institutions.
    • LOINC Code: 73837-7 Galactose-alpha-1,3-galactose (Alpha-Gal) IgE Ab [Units/volume] in Serum.
  • Skin tests for reactions to allergens like pork or beef may also be used to diagnose AGS.

Diagnosis

AGS is diagnosed through a detailed patient history, physical examination, and a blood test. The blood test looks for specific IgE antibodies the immune system produces in response to alpha-gal.

Allergy skin testing may also be used to help diagnose AGS.

Reporting cases

AGS is not a nationally notifiable condition; however, your state may require reporting. Please check with your state and local health departments about reportable diseases. All jurisdictions are encouraged to share information on AGS with members of CDC's Rickettsial Zoonoses Branch to better understand national trends.

Alpha-gal Syndrome Case Report Form [PDF – 2 pages]

To submit case report forms for AGS, email the case report form to rzbepidiag@cdc.gov or fax it to 1-404-471-2737.

The Council of State and Territorial Epidemiologists (CSTE) approved a position statement standardizing a case definition for alpha-gal syndrome (AGS) in 2021. The case definition is for surveillance purposes only and does not replace a clinical diagnosis by a healthcare provider.

Surveillance case definition [PDF – 12 pages]

A standard surveillance case definition provides consistent laboratory and clinical criteria to ensure that data captured across multiple jurisdictions are comparable.