Apple Watch leaving burn marks on wrist

Hi

If you experience redness, swelling, itchiness or any other irritation or discomfort on your skin around or beneath your watch or band, Apple recommends that you remove your Apple Watch and consult a doctor / physician before wearing it again.

Skin reactions can be a result of various causes including:

• Allergies (eg to nickel).
• Extended exposure to irritants (eg soap or sweat).
• Environmental factors.
• Wearing the band too tightly or too loosely.

More information, including tips from Apple:

• Cleaning and wearing Apple Watch - Apple Support

  Includes "Tips to avoid skin irritation, or if you have allergies or skin sensitivities".

• Wearing your Apple Watch - Apple Support
• See under "Skin Sensitivities":

  Important safety information

Note that there is no model of Apple Watch that has no metal or nickel touching the skin; the magnets in all models of Apple Watch contain some nickel.

If you are considering buying a different band, note that Apple recommends using only Apple-branded or Apple authorised bands with Apple Watch:

• Band care information
• Buy Apple Watch Bands - Apple

For information about what is in each of the Apple bands, see the resource linked in my previous reply:

Wearing your Apple Watch - Apple Support

Take your son to a doctor. That's an allergic reaction. If I had to guess, I'd say it's likely he has a nickel allergy.