bald spot on dwarf hamster

Question
My wife's black russian dwarf hamster has a bald spot under his left ear that feels like a slight bump, it doesn't seem to be bothering him.  He is in a cage by himself so there isn't any fight injury.  Your opinion would be greatly appreciated, thank you.

Answer
How long has the bald spot been there and how old is the hamster? Is the activity level of the hamster normal and he is eating and drinking normally? If the hamster is acting normal and the bald spot isn't growing, than it is probably just a growth. To find out if the growth could be cancerous than the vet would have to run tests. If he is acting normal than I wouldn't worry too much about the growth. If the bald spot continues to grow than he may have a case of mites and the vet would have to give him antibiotics for the mites. Also what type of bedding are using? Sometimes a hamster can lose fur because of allergies. Pine and ceder and the most known causes of allergies and on rare occasions aspen can cause allergies.