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

Medical Device Problem Code	Patient-Device Incompatibility (2682)
Health Effect - Clinical Code	Hypersensitivity/Allergic reaction (1907)
Date of Event	03/31/2026
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
A review of the complaint revealed that the patient was prescribed the zio monitor for a 14-day wear period.The patient does not have sensitive skin and does not have a history of reaction to medical adhesive.The exact cause of the reported event cannot be determined.However, skin irritation is a known inherent risk of the device.Zio monitor clinical reference manual warnings state the following: do not use the zio monitor on patients with known allergic reaction to adhesives or hydrogels or with family history of adhesive skin allergies.Patient may experience skin irritation.If skin irritation such as severe redness, itching or allergic symptoms develop, remove the zio monitor 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 fda 3500a 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 skin irritation allegedly caused by the zio monitor.The patient experienced itching at the application site.The device was removed.The patient reported being evaluated by an hcp, who diagnosed an allergic reaction and prescribed prednisone to treat the reaction.

• Brand Name: ZIO MONITOR
• 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 ; 6094600577
• MDR Report Key: 25037791
• Report Number: 3007208829-2026-00165
• Device Sequence Number: 21425102
• Product Code: DSH
• UDI-Device Identifier: 00869770000241
• UDI-Public: (01)00869770000241(17)260810
• Combination Product (Y/N): N
• Initial Reporter Country: US
• PMA/510(K) Number: K202359
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Consumer
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial
• Report Date (Section B): 04/29/2026

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
• Operator of Device: Lay User/Patient
• Device Expiration Date: 08/10/2026
• Was Device Available for Evaluation?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 04/12/2026
• Initial Report FDA Received Date: 04/29/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• 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 Age: 69 YR
• Patient Sex: Female