Thick Toenails

The Keratin Story

This article is on the subject of thick toenails. Yuck, you might say... but let's look at those key features common to nail problems.

• Thick and dense

• Deformed

• Infected

An ingrown toenail is not part of the keratin story; you can read about this elsewhere on this site.

Keratin

Rams and rhinos have horns of keratin, a protein structure similar to that of humans.

Unlike the elephant tusk, which is made of similar material to teeth, the ram's horn, and that of many animals, comes from the same protein found covering skin. While fingernails have the power of a weapon, toenails are just tucked away and unnoticed. These extensions of our body are often weaponised and play an essential part in animal protection, but less so for humans.

Because nails are hidden away until a problem arises, they are ignored. Nails are exposed in sandals where the climate is warmer, and nails and toes are more visible. But for us, in the UK, the majority of feet are covered up until we reach those sunny days and heat waves. Age does create changes, and I liken this to the rings of a tree; the older we are, the greater the chance of thickened nails.

Nail Growth and the Sensitive Matrix

These densely packed cells form a flat structure at the end of the toe, positioned over a bone called a phalanx. In shoes, nails are exposed to pressure.

Growth

Nail growth is slow at around 0.1mm a day and is exposed to damage along its sensitive ‘growth cells’ called the nail matrix. Growth can be altered if the nail is exposed to trauma.

The nail matrix is shown, and the white-coloured lunula, the half-moon-shaped area in front of the cuticle, is also sensitive to damage. The other parts of the nail bed, easily exposed to injury, include the end of the nail (hyponychium). The attachment is sensitive to damage, and if you, like me, have ever crushed a fingernail or lifted the edge, you will understand how uncomfortable this is. The end of the toe is packed with sensory nerves.

Fig.1. Cross-section through the end of a digit (toe and finger)

Early damage in childhood

Many of us have a damaged little toenail (Fig.3). A tight shoe can lead to permanent damage before we start using our feet. As we age, our nails become more resistant than in childhood, but sports or other activities still damage them, and few reach upper ages without some thickening or discolouration.

Damage Leads to Thick Toenails

Fig.2. Haematoma after a 3-mile walk. Months later, recovery has restored the nail, or has it? See Fig.3 below.

Nail damage leads to permanent changes that are not always evident.

The fourth toenail in the left-hand image appears dark. This arose after a sixty-minute walk in light trainer-type shoes, and then went clear after a few weeks. The third toe and nail are normal, but the darkness seen with the 4th toenail is blood under the nail. This is called a blood pool, which goes hard and is called a haematoma. The simple act of walking 3 miles allowed the toe to piston back and forward in the shoe. This tore the small blood vessels between the nail and the softer nail bed. We call this a sub-ungual haematoma. Sub-ungual refers to under the nail. While the nail settled long-term, it thickened up. (See below at four years on.) This is the story of most nails, except the thickness may vary.

Fig. 3. Long-term effects of nail damage five years after the 4th toe was damaged by shoe pistoning. The 5th toe was destroyed as a child and thickened over the decades. Male aged =69.

It is essential to ensure the shoe is used for the right task, fits well, and does not move back and forth - this is the pistoning effect.

Deformity

A nail that is thickened has the medical title - onychauxis (oni-cork-sis). Simple filing and careful cutting will take care of most problems, but when the nail is deformed, not only does it take on darker hues, but the shape is distorted. This is called onychogryphosis (oni-ko-gri-fosis). This problem not only makes cutting difficult, but the bulk also grows upwards, and if left, it resembles a ram's horn. In fact, one of the names given to the nail has been ram's horn nail.

Fig. 4. Ram's horn nail. Te What Ora Health New Zealand. Courtesy DermnetNZ.org

Neglected nails can lead to many problems in the toes. Fig.4. illustrates deformity, and the nail is not only difficult to manage, but also presses on adjacent skin, causing pressure damage. In patients with a lack of sensitivity (diabetics) and those with mental diseases, the risk of infection and skin healing becomes accelerated.

Far from being a cosmetic problem, the condition is best managed by podiatrists trained to deal with it, usually without the need for local anaesthetic.

Infections in nails

The keratin horn in Fig.4 is thick and dense, but not all nails are so illustrated. Infection arises when the nail quality is impaired and breaks down. I liken this to a piece of an old tree branch, which is soft and broken down. In the case of human nails, the crumbly effect more often yields a fungal (mycotic) infection.

Fig.5. Nail affected with fungal infection.

Fungi tend to prefer damaged nails, and given the fact that a foot is encased in a warm and dark environment, perfect for growing mushrooms, these dermatophytes thrive. (The highlighted link will offer a broader perspective on conditions like athlete's foot.)

The yellow-brown discolouration, characterised by a crumbly honeycomb appearance, is very difficult to manage. Most pharmacy products, when applied, fail because they cannot penetrate the nail. While filing helps, cross-infection is possible if the file is shared. Replaceable emery style files are better.

There are two approaches to managing nail infections. The type of fungus needs to be confirmed by a sample sent to a medical laboratory. Not all nails actually harbour fungal hyphae, a sort of tentacle-like projection.

The nail needs to be reduced, and this is often best performed by podiatrists. Modern drills have coolant sprays and dust extractors to avoid breathing in the fine particles. Once the nail has all the damage reduced, medication can be applied. Oral medication is possible, but it works better on finger nails than toes. Doctors are often reluctant to prescribe antifungals due to their potential impact on the liver, necessitating regular blood tests during treatment.

Removing a nail entirely under local anaesthetic can be worth considering in cases of poor nails. The nail can be permanently destroyed, or the nail can be treated as it regrows, with the hope that new nail cells will be purged. From a cosmetic point of view, a nail free of infection looks better on the beach or around swimming pools. Of course, regular gym users can pass on some bugs, although properly treated water is less likely to be contaminated than in showers and locker rooms.

Footwear that has been used with an infected toenail is another matter, as leather can hold fungal spores. The shoes should be discarded, never shared, or fumigated with an antifungal agent. The link will offer more information on fumigation and shoe hygiene.

Helpful books about feet from the author include An Introduction to the Foot & Common Problems in the Adult and Foot Health Myths, Facts & Fables. Go to the home page to discover more from the author.

ConsultingFootPain is part of Busypencilcase Communications & Publishing. Advice can be sought by sending a message using contact on this site's home page

Thanks for reading, ‘Thick Toenails’ by David R. Tollafield