Are your toenails looking a little…off? Don't automatically assume it's just a fungal infection! A surprising number of nail problems are actually caused by mechanical issues, and misdiagnosing them can have serious consequences, especially if you have diabetes.
This clinical review sheds light on a crucial, often overlooked, aspect of nail health: the impact of physical trauma. You might be surprised to learn that physical trauma from everyday activities is actually a more common cause of distorted toenails (onychodystrophy) than fungal infections (onychomycosis) in many clinical practices. Think about it: ill-fitting shoes, or foot problems like Morton's toe (where the second toe is longer than the big toe), bunions (hallux valgus), stiff big toe joints (hallux rigidus), or even flat feet can put unusual stress on your toes. This, in turn, can dramatically alter how your nails grow. The experts emphasize that when evaluating troublesome toenails, it's vital to look at the whole foot, and how it functions when you're standing and walking, along with a close inspection of your footwear. Are your shoes too tight? Too narrow? Do they provide enough support?
Trauma-related nail problems don't just stop at distortion. They can actually increase your risk of developing a secondary fungal infection. And this is the part most people miss... That's why it's so important to get a proper diagnosis through lab tests before jumping to the conclusion that it's just a fungus. Furthermore, foot structure issues can worsen nail psoriasis through a process called koebnerization. This means even if you successfully treat the psoriasis, your nail issues might persist if the underlying mechanical problem isn't addressed.
The review goes on to describe a whole spectrum of nail changes that can be caused by repetitive stress. We're talking about things like painful calluses under the nail (subungual heloma), thickening of the skin around the nail (onychophosis), nail separation from the bed due to friction (frictional onycholysis), white spots on the nails (leukonychia), dark lines (melanonychia), horizontal lines across the nails (Beau lines), nail shedding (onychomadesis), and even the nail growing into the skin at the cuticle (retronychia). Even arthritis in the joints of your toes could potentially play a role by affecting the nail matrix, the area where the nail grows from.
But here's where it gets controversial... While these mechanical issues can affect anyone, they're particularly concerning for people with diabetes. Diabetes brings its own set of challenges, including high blood sugar (hyperglycemia), nerve damage (neuropathy), and blood vessel problems (vasculopathy). All of these can contribute to nail problems, on top of the foot problems that people with diabetes are already prone to, like ingrown toenails and fungal infections. Now, combine altered pressure distribution on the foot, distorted nails, and the impaired ability to heal – and you have a recipe for foot ulcers.
The authors stress that quickly identifying and treating fungal infections and ingrown toenails in people with diabetes is a crucial preventative step. Effectively managing these mechanical and structural nail problems in this high-risk group can significantly reduce the risk of serious complications like ulcers, bone infections (osteomyelitis), and even amputation.
So, what can you do? Be proactive about your foot health! Make sure your shoes fit properly, address any underlying foot problems, and see a podiatrist or dermatologist if you notice any changes in your nails. Early intervention is key to preventing serious complications.
Reference: Ricardo J W. Evaluation and Management of Mechanical and Structural Nail Disorders: A Clinical Review. J Am Acad Dermatol. 2025;doi:10.1016/j.jaad.2025.11.025.
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Each article is made available under the terms of the Creative Commons Attribution-Non Commercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) .
Now, I'm curious: have you ever suspected a nail issue was caused by something other than a fungal infection? What steps have you taken to address mechanical nail problems? Share your experiences and thoughts in the comments below!
