Development of a single-step lateral flow immunoassay for penicillin G allergy screening

Penicillin, a widely used narrow-spectrum antibiotic, remains the most frequently reported drug allergy. However, less than 20% of individuals reporting a penicillin allergy are truly allergic. Antibiotic allergy de-labeling is, therefore, essential to prevent adverse reactions and inappropriate treatments. We present the first single-step Lateral Flow Immunoassay for penicillin G allergy screening, offering real-time visual results at the point of care. The detection limit of 0.3 IU/mL of the assay, equivalent to 0.72 µg/L, determined in artificial human serum, enables the identification of class 0 allergy patients (< 0.35 IU/mL) per the RAST scale, distinguishing between low, medium, and high allergy severity groups with a smartphone reader over a dynamic range of 0.3-10 IU/mL. This lateral flow assay for penicillin allergy screening enables a shift in allergy diagnostics from centralized laboratories to more accessible point-of-care settings, including doctors' offices and self-testing.