Some owners of the Apple Watch Series 12 and Apple Watch Ultra 4 are reporting skin irritation beneath the watch’s sensor area. Users have described redness and a burning sensation in discussions on Reddit and Apple-focused forums.

The reports do not establish a confirmed cause, and it is not clear how widespread the issue is. Some affected users have questioned whether changes to the latest models could be involved, including more frequent heart-rate readings and updated sensor hardware.

What Apple Watch owners are reporting

The Apple Watch Series 12 and Ultra 4 measure heart rate every five seconds. Both models also include a larger ECG electrode surface, photodiodes arranged in a ring and larger green LEDs. Users have wondered whether one of these changes might contribute to irritation, but there is currently no evidence identifying a specific component as the cause.

Skin reactions are not new to Apple Watch owners. Similar complaints have been associated with earlier models, and individual experiences vary. Some users say the irritation improved after they continued wearing the watch for a period of time. Others reported improvement after cleaning the rear of the watch and the band, while some returned their devices.

Apple’s guidance for skin irritation

Apple says reactions may result from wearing a band too tightly or too loosely, or from irritants trapped between the watch and skin. Sweat, soap, sunscreen and lotion can remain under the watch, particularly after exercise or contact with liquids.

Apple also notes that some Apple Watch models contain nickel, although the amount is below European Union limits and is considered unlikely to cause a problem. The watch case and certain bands contain trace amounts of acrylates and methacrylates from adhesives. Apple says its design keeps those substances away from the skin.

How to reduce the risk of irritation

  • Make sure the band fits securely without being too tight.
  • Keep the Apple Watch, band and skin clean and dry.
  • Clean the watch after workouts or exposure to sweat, soap, sunscreen or lotion.
  • Stop wearing the watch and seek medical advice if irritation develops.

Apple advises anyone experiencing redness, swelling, itchiness or other irritation to consult a physician before putting the watch back on. That guidance is especially relevant if cleaning the device and adjusting the band do not resolve the reaction.