Most commonly, the skin flakes in the ear are due to seborrheic dermatitis, commonly known as dandruff. Another common cause is psoriasis. Even chronic scratching of the ear can produce a rash with flaking, called lichen simplex chronicus.
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
- acne (lots of hair follicles and sebaceous glands there)
- benign and malignant skin growths, like seborrheic keratoses, basal cell carcinoma and squamous cell carcinoma
- a skin form of lupus, called discoid lupus erythematosus
- shingles, also known as herpes zoster
- impetigo (a bacterial infection)
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.