Dry, itchy, scaly skin on your outer ear is likely due to dermatitis (inflammation of the skin). This can be due to many triggers including genetic predisposition, soap/shampoo used, earplugs etc. The treatment of outer ear dermatitis include a short course of steroid cream or ointment.
It is inportant to avoid the potential trigger if possible. Once the dermatitis has resolved, you should keep your outer ear mosturized with a skin mosturizer.
I would suggest a visit to a General Practitioner, Dermatologist or ENT Specialist for an assessment.
Hope this helps and all the best!