Answer to Case 503

Answer: Demodex folliculorum, the follicle mite.

What is it doing on the toe? Well, toes have follicles too! It's true that we generally think of these little mites on the face, but they can be found anywhere on the skin. Interestingly, dogs (and possibly other animals) can get severe infection of their paws from Demodex species (called demodectic mange). In humans, Demodex are mostly considered to be harmless inhabitants of our skin.

Here is a nice side-by-side view of the 2 images in this case:

Note the presence of 8 legs in the adult form (mites are arachnids and not insects). Thanks again to Florida Fan for these lovely images!