MAUDE Adverse Event Report: IRHYTHM TECHNOLOGIES, INC ZIO XT; RECORDER, MAGNETIC TAPE, MEDICAL

Medical Device Problem Code	Patient-Device Incompatibility (2682)
Health Effect - Clinical Code	Skin Inflammation/ Irritation (4545)
Date of Event	12/08/2025
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
A review of the complaint revealed that the patient wore the zio xt for the full 14-day prescribed wear period.The patient has sensitive skin and a known history of reaction to medical adhesive.The exact cause of the reported event cannot be determined; however, the patient¿s preexisting sensitivity and history cannot be ruled out as a contributory factor.The zio xt clinical reference manual ¿ ukca provides a warning that states, ¿ prior to monitor application, examine the skin area of the patient for certain skin conditions (such as dermatitis, eczema, rashes/hives), acute/chronic cutaneous infections or irritation.If skin irritation such as severe redness, itching or allergic symptoms develop, remove the zio xt patch from the patient¿s chest." this event is being reported per 21cfr803 as a serious injury.This report does not constitute an admission by rhythm that the product described in this report has any defects, or has malfunctioned.These terms are included in form fda3500a and are fixed terms for selection created by the fda to categorize the type of event solely for the purpose of regulatory reporting.
Event or Problem Description
The patient presented to their healthcare provider (hcp) with signs of skin irritation allegedly caused by the zio monitor.The patient experienced itching, redness, spots and a rash.The patient was prescribed hydrocortisone cream.

• Brand Name: ZIO XT
• Common Device Name: RECORDER, MAGNETIC TAPE, MEDICAL
• Manufacturer (Section D): IRHYTHM TECHNOLOGIES, INC; 699 8th st suite 600; san francisco CA 94103
• Manufacturer (Section G): IRHYTHM TECHNOLOGIES, INC; 6550 katella avenue, suite 200; cypress CA 90630
• Manufacturer Contact: tara mackinnon ; 699 8th st suite 600; san francisco, CA 94103
• MDR Report Key: 24155882
• Report Number: 3007208829-2026-00023
• Device Sequence Number: 9205158
• Product Code: DSH
• UDI-Device Identifier: 00869770000203
• UDI-Public: (01)00869770000203(17)260415
• Combination Product (Y/N): N
• Initial Reporter Country: UK
• PMA/510(K) Number: K121319
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Foreign,Consumer
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial
• Report Date (Section B): 01/22/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Expiration Date: 04/15/2026
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 12/05/2025
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 12/30/2025
• Initial Report FDA Received Date: 01/22/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Required Intervention
• Patient Sex: Female