COVID Vaccine-Related Swelling Lasts Longer Than Initially Reported

New research has discovered that axillary lymphadenopathy, a type of swelling in the armpits, detected after COVID-19 mRNA vaccination lasts longer than reported in initial vaccine clinical trials.

The duration of axillary lymphadenopathy detected by breast ultrasound after COVID-19 mRNA vaccination is longer than previously reported in initial vaccine clinical trials.

A new research published in ARRS’ American Journal of Roentgenology (AJR) shows that axillary lymphadenopathy detected by breast ultrasonography following COVID-19 mRNA vaccination lasts longer than reported in initial vaccine clinical trials.

“The prolonged resolution time supports a follow-up interval of at least 12 weeks for suspected vaccine-related lymphadenopathy and avoidance of delaying screening mammography after vaccination,” wrote corresponding author Michele B. Drotman, MD.

Left: Transverse image of left axilla on initial breast ultrasound, 19 days after the first dose of Pfizer COVID-19 vaccination to left upper extremity, demonstrates the increased cortical thickness of 4 mm (arrow). Right: Transverse image of left axilla on follow-up ultrasound, 100 days after first COVID-19 vaccine dose, demonstrates the cortical thickness of 2 mm (arrow), consistent with resolution of left axillary lymphadenopathy (arrow). The patient underwent a second dose 2 days after the initial ultrasound. Credit: American Roentgen Ray Society (ARRS), American Journal of Roentgenology (AJR)

Drotman and the Weill Cornell Medicine team extracted health record data from 111 patients (mean age, 52 years) with unilateral axillary lymphadenopathy ipsilateral to Pfizer or Moderna COVID-19 vaccine administration—performed within 8 weeks prior and detected on breast ultrasound (January 1-October 1, 2021) who underwent follow-up ultrasound examinations at 4-12 weeks.

In this single-center study, axillary lymphadenopathy ipsilateral to COVID-19 mRNA vaccination resolved after a mean of 97 days since detection by breast imaging and 127 days since the first dose. Longer times to resolution were observed with Moderna (rather than Pfizer) vaccination, receipt of the second dose after presentation, and thicker cortical thickness at presentation.

“The presence of subclinical lymphadenopathy and the long resolution time of lymphadenopathy,” the authors of this AJR article noted, “should reassure radiologists and patients when lymph nodes suspected to be vaccine-related persist over multiple visits.”

Reference: “Time for Resolution of COVID-19 Vaccine-Related Lymphadenopathy and Associated Factors” by Elizabeth G. Lane, Carolyn S. Eisen, Michele B. Drotman, Katerina Dodelzon, Eralda Mema, Charlene Thomas and Martin R. Prince, May 2022, American Journal of Roentgenology.
DOI: 10.2214/AJR.22.27687

COVID-19MRNAVaccinationVaccineWeill Cornell Medicine