Hi, Dermatologic conditions are difficult to diagnose without seeing them. There are several different types of peeling. One of the most common is destroyed nails that almost look like tree bark. This is due to fungal infection and there are several very effective and cheap medicines for it. Then there is vitamin deficiency or iron deficiency. The key point is that while infection goes from the outside and hits the whole nail, the deficiency happens at a particular time. There is a firm line on the nail from before and after. Before the deficiency and outward, the nails aren t touched. After the deficiency, then there is a line where the nails are of poor quality but, not tree bark. There can be pits in nails. This is different. This is an immune attack on spots caused by psoriasis. There can be plain chemical exposure. The skin is almost always affected and not just the nails. There can be a line up and down the nail like a ridge. This can also be vitamin deficiency but diabetes or metabolic conditions can also be the cause. Basically, it depends on the particular appearance. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Matt Wachsman, Addiction Medicine Specialist