Diabetic Toenails: Watch for Change

Published on February 23, 2017 by Keisha Smith, MA, CWCMS

Changes in the diabetic foot can happen fast: here are the signs and types clinicians in wound care need to look for.

As a wound care professional, chances are you’ve treated a number of nail conditions and abnormalities that occur among the general population. But when you’re working with diabetic patients, noticing and identifying variations is even more crucial. This is because change can happen more rapidly in the diabetic foot, and pathologies in diabetic toenails can ultimately lead to skin breakdown, foot ulcerations and infection. So, what causes the nails to change? What exactly should you look for? We’ve got you covered.

Why the Change?

Changes in the diabetic toenails are usually due to:

  • Poor circulation
  • Trauma – which often goes unnoticed due to neuropathy
  • General susceptibility to fungal infections – resulting from high levels of glucose in the blood

What to Look For in Diabetic Toenails

The first toenail change you’ll notice in diabetic patients is likely to be discoloration. Most have some yellowing of the nails, though the shade and involvement can vary. Discoloring may start at the distal edge (tip), and run all the way to the root of the nail bed. The shade can be a light yellow, brown-tinged, or even canary yellow.

When you see red, brown or black toenails, it’s often a subungual hematoma – or collection of blood under the nail – which may result from acute or chronic trauma.  Since cancerous melanoma can lead to black toenails, once you’re able to rule out trauma, check for a malignancy.

Types of Nail Changes and Conditions

In addition to nail discoloration, be on alert for these types of changes in the diabetic foot:


A thickening or hypertrophy of the nail plate of the toenail (without deformity). It typically includes discoloration or a loss of translucency.  Though onychauxis can be a natural part of aging, it is also a common symptom of diabetes. Unfortunately, thick toenails can be very difficult for the patient to maintain, which may result in deformities such as a Ram’s Horn (described below). In the WCEI Blog, “Diabetic Toenails, Top Tips for Proper Trimming,” we offer advice on keeping diabetic nails at the optimal length. You can download a handy neuropathic foot exam guide too.


Also known as an ingrown toenail, this is when the nail grows into the subcutaneous tissue along the sides of the nail. In a non-diabetic, this can be a very painful condition. In a diabetic patient, however, peripheral neuropathy may inhibit sensation, and the condition may progress without the patient’s notice.  You’re more likely to observe ingrown toenails in a chubbier toe, and especially among those whose feet tend to swell. Other causes include ill-fitting shoes, improper cutting of the nail, or previous trauma.


Also known as Ram’s Horn, this is a thickening of the base of the toenail with severe deformity. The nail will have a very curved, hooked appearance. It’s often caused by infrequent nail-cutting, which is common among diabetic patients, who are often afraid to trim their nails or embarrassed to ask for help (because of onychauxis and other nail pathologies). Trauma, psoriasis, or foot-to-shoe incompatibility can lead to a Ram’s Horn.

Pincer or Trumpet Nail

An extreme curvature that increases distally, like a trumpet or cone formation. As the nail rolls or curls inward, it can cause skin breakdown and ulceration, and be extremely painful for the patient (unless neuropathy is also present).  Once again, ill-fitting shoes can add to the problem, as well as bone spurs and fungal infections. Some patients also have a hereditary predisposition toward nails that curl in this formation.

Plicatured Nail

The surface of the nail is flat, while one or both edges of the nail plate are folded at a 90-degree angle down into the soft tissue margins, much like the shape of staple. While heredity can play a role, the culprit is likely tight shoes or injury.


A superficial infection of the epithelium lateral to the nail plate. Poor nail cutting is often the culprit. As with other infections, it presents with erythema (redness), edema (swelling), tenderness along the nail fold and fluctuance (a wavelike motion that you’ll feel when palpating the skin).


The term for a fungal infection of any part of the nail. As mentioned earlier, diabetic patients are more susceptible to fungi. At the outset, fungal infections are asymptomatic, progressing to cosmetic changes that may alarm the patient – such as discoloration.  However, if left untreated, onychomycosis can cause pain, loss of dexterity, and paresthesia (numbness or tingling).  Ultimately, it can interfere with standing or walking.

Keep an Eye Out

Regular visual exams are an essential step when caring for diabetic patients. And when it comes to identifying nail problems that can result in future foot ulcerations, earlier is always better. Footwear assessment is also key to diabetic foot health, given the role that an improper fit can play in creating nail deformities.

By knowing the types of diabetic foot abnormalities and being aware of nail changes, you can help take better care of your diabetic patients and intervene with proper treatment as soon as possible.

What Have You Seen?

What are your experiences with diabetic patients and toenail care? Do you have a challenging case you’d like to share? We would love to hear your stories, along with any advice or insights you have on this topic. Please leave your questions below.

Wound Care Education Institute® provides online and onsite courses in  Skin and Wound, Diabetic and Ostomy Management. Health care professionals who meet the eligibility requirements may sit for the prestigious WCC®, DWC® and OMS national board certification exam through the National Alliance of Wound Care and Ostomy® (NAWCO®). For more information see wcei.net.

Keisha Smith, MA, CWCMS

Keisha Smith, MA, CWCMS, is a freelance digital marketing consultant who works with clients in healthcare, law and behavioral health. Her specialties include content creation, social media and brand clarity. As an eight-time Wild On Wounds conference staff member and an alumna of WCEI's training program for wound care marketing professionals, she loves the exceptional passion of clinicians who treat wounds. She frequently finds herself advising friends and family to keep their minor wounds warm and moist.