Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.
Now this would be an odd area for ringworm (unless he was licking your feet and you had ringworm on that toe). Still, can you tell me:
Is there just hair loss or are you seeing any scaling, crusting, or ulceration of the skin?
Any tissue swelling or redness?
Does he appear to itch the area?
If possible, could you take a photo of this? If you can do so and post them online, I am happy to have a look (since it will let me see what you are seeing). To post them, you can either use the wee paper clip on the tool bar (How To). Or you can post them on a 3rd party site (ie Flickr, Photobucket, etc) and paste the web address here.