Dermatitis

Dermatitis is a very sore and itchy skin complaint. It’s common in humans, and can also be suffered by cats and dogs. If your kitty has dermatitis, it could be caused by a number of underlying conditions, and your vet will carry out tests to find out which one. Treatments may include anti-inflammatory medication, as well as antihistamines.
Skin cancer

Skin cancer is more common in pure white cats or those with white patches. Just like fair skinned, blue eyed people, white cats can easily get sunburn. Vets often advise owners to put sunscreen on the ear tips of white cats, but you must only use products designed for pets
If cancerous growths are treated in the early stages, recovery is often good. These growths can often appear as crusty lesions. However, any unusual lump that’s suddenly manifested should always be looked at by your vet. Treatment depends on the type and location of cancer. Skin cancer in the ear often means loss of the outer ear flap. Though it may look unsightly it doesn’t affect hearing.