I have recently noticed some small dark spots on the bottom of my toe. I'm pretty sure they are localized. They seem to accompany an area of unusually dry skin, and the irritation and itchiness is comparable to a mild blister. The small spot do seem to harbor some fluid, but again they are very small. I'm don't think it's hygene or humidty related. I'll admit it's an area that doesn't get the hygenic treatment that most of my body gets, but the reason I say it is because I had the same spots on my fingers about a year ago (Although it was only 2 or 3 at a time on only a couple occasions). If it were hygiene related, I highly doubt they would have been on the sides of my fingers because I have a near obsessive compulsive habit of washing my hands, and my hands are never really dry, while the undersides of my toes become dry quite often. Parasites in my bed have come to mind, but my fiancee shares my bed and has not had the same problem to my knowledge. What may also be worth noting is that they eventually fade and the raised skin dies and peels off over time from the center outwards.