My dog’s ear is crusty :(( from too much scratching or ear mites????

Hello - this is interesting, and not necessarily from mites or scratching.  It would be interesting / unusual if they managed to make it bald by scratching the very outside tips of the ear alone.  I therefore wondered about other causes of hair-loss in dogs, including vasculitis - where disease arrives along the veins.  This could be urgent and needs to be triaged by a vet.  Other possibilities may include Ringworm or Demodex, endocrine diseases e.g. hypothyroidism and so on.  The rest of the patient may give some context here, hence the need for a clinician who can examine the whole!   Please will you let us know how you get on?

(Ps because Ringworm is on the list, please practise good hygeine and wear goves to touch the lesion for now)