It appears that you may be having fungal infection
in the outer ear fold. This could result from sweat accumulation, seborrheic dermatitis
and lack of hygiene.
While showering, do clean behind ears as otherwise infection may develop. If you have severe dandruff
, you may need similar ointments
which you are using for the scalp, folds of nose etc.
Keep the area clean. Wipe regularly with clean, soft cloth. Eat balanced diet. Drink 1-2 litres of water daily. Avoid cleaning inside of ear roughly. Avoid using cotton ear buds as they can increase chance of infection.
Wishing good health.