Hair loss around ears - what can it be?

Hi, my dog has been experiencing some hairs loss around his ears. Around a month ago I took him in as he had scabs on his skin which were suspected to be mange mites. Since then he has been dewormed and has taken the appropriate medication. He also had some hair loss on the edges of his and some of it looked waxy/clumped together. He made a full recovery from both of these issues but.. Just a few days ago the same type of hair loss reappeared and I’m not really sure what’s wrong - would anyone have an idea? Pictures attached. 

Hello!  The first thing to say is that your vet is the go-to person for this.  They know the case, are responsible for your dogs' care and can do tests and prescribe accordingly.   However, I do have some questions that you mite (pun!) like to think or ask them about....

1) You say that 'appropriate medication' was given, but not what it was appropriate for?  There are multiple species of mites causing mange (mange just means 'mite infestation').  There are also various other critters / diseases that could cause signs like this, even if mange was diagnosed previously.  You need to use a treatment that has been proven to work on the cause and to do this, it is important to know exactly what the cause is. The level of Itchiness is the first crucial step to identifying itchy mites (or even allergy) vs non itchy mites (demodex) or something none mitey and non-itchy like ringworm (warning- zoonotic - can be passed on) or endocrine disease.  Having established what is most likely, your vet may still need to do tests to make sure.  2) How long was the initial treatment supposed to last?  Does it simply need repeating?   3) If this is down to the same mite and they keep recurring, why is this?  - as it can be a sign of low immunity and therefore linked to underlying disease, such as hypothyroidism for example.   I'm sorry to raise more questions than answers, but feel that it would be well worth seeing your vet again.