How do i tell if the skin on top of my big toe is dry or fungal? i've been applying moisturizing cream for a few months and there has been no change.

Fungus?: One easy way is to have a podiatrist take a small portion of skin and send to lab to determine if its a fungus or not. Does it itch?

Sweat: Although it could be a fungal infection, try uses deodorant to decrease sweat around the area. By using spray deodorant, this is a preventive action for future infections and takes away possible spread of fungal infection. The deodorant will help stop evaporation of sweat from your skin and may help prevent future fungal attacks if moisturer doesn't work. If all else fails, see a podiatrist.

Skin: Your podiatrist or dermatologist can scrape a skin sample and send it to the laboratory for examination and report. That report may reveal whether there is fungus in the tissue or not.If there is no fungus problem then a skin punch biopsy could reveal a condition such as psoriasis eczema or contact dermatitis, to suggest a few possibilities.