Psoriasis, seborrheic dermatitis and eczema can cause flaking, scaling, redness and itching on the back of the ear as well.
There are a number of disorders that can cause a rash in the ear. The conchal bowl (the indented area that leads to the ear canal) can be involved with a number of other skin conditions, including
Discoid lupus erythematosis, ear
Squamous cell carcinoma (skin cancer) of the ear
These conditions require different treatments and may require some additional diagnostic tests. I recommend a consultation with a dermatologist for a more definitive diagnosis and treatment of ear flaking.