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	Skin Inflammation/ Irritation (4545)
Date of Event	04/09/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
The patient reported seeking evaluation from a healthcare provider (hcp) for itching, blisters and alleged scarring at the zio monitor device application site.The device was removed and discarded.According to the patient, their hcp prescribed triamcinolone acetonide cream.
Additional Manufacturer Narrative
The zio monitor was not returned to irhythm for evaluation.A review of the complaint revealed that the patient wore the zio monitor for approximately 11 of the 14 prescribed days.The patient does not have a history of reaction to medical adhesive or sensitive skin.The cause of the reported event cannot be determined.Cutaneous scarring is generally associated with injury extending into the dermis and subsequent collagen remodeling during the healing process.Skin findings observed at device removal following short-term wear (up to two weeks), in the absence of documented dermal injury, are more consistent with transient inflammatory or irritant skin reactions associated with adhesive use, such as erythema, edema, induration, or post-inflammatory pigment changes.Based on the available information, the reported skin findings are not consistent with mature scar formation at the time of device removal, as scar maturation and remodeling typically occur over a period of months.Skin irritation is a known inherent risk of the device.The device manual warnings section read as follows: do not use the zio monitor on patients with known allergic reaction to adhesives or hydrogels or with family history of adhesive skin allergies.If allergic symptoms, severe skin irritation, or signs of skin infection develop, remove the device from the patient¿s chest and discontinue wear.Reaction to adhesives may include severe redness and itching, hives, and blisters.Contact your healthcare provider and customer care to report the reaction.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.

• 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: 25210590
• Report Number: 3007208829-2026-00179
• Device Sequence Number: 21424951
• Product Code: DSH
• UDI-Device Identifier: 00869770000241
• UDI-Public: (01)00869770000241(17)260831
• 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): 05/18/2026

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: 08/31/2026
• Was Device Available for Evaluation?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 04/20/2026
• Initial Report FDA Received Date: 05/18/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 03/04/2026
• 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: 43 YR
• Patient Sex: Female