Hey there and thank you for your question and the attached photos.
I agree a vet visit is wise here.
It is possible the two lesions are related and due to e.g. allergies, a fungal infection like ringworm, mites or a bacterial infection.
It could also be that they are unrelated and the ear lesion is due to e.g. ear mites or a localised ear infection while the wrist lesion is caused by over grooming linked to wrist pain (perhaps due to arhritis if your cat is an older cat).
I'd use an ear cleaner if the ears are waxy or smelly.
I would also bathe the affected areas twice daily in a dilute Chlorhexidine (Hibiscrub) wash. You can get this from any pharmacy and it is inexpensive. You dilute it 1:10 in water and apply with cotton wool. Leave it on for 5-10 minutes, then rinse with water and pat dry.
Ensure your kitty is up to date with a broad acting parasite prevention.
Consider a buster collar to protect the skin temporarily if the licking is excessive.
The vet should examine the skin and perhaps swab/smear the areas to get a diagnosis. Your cat may need some prescription medicine such as anti itch medicine or oral antibiotics.