‘What do rams and rhinos have in common with feet?’

You might wonder what rams and rhinos have in common with feet? Unlike the elephant tusk which is made of material similar to teeth and sadly sought after, the rhino 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, unnoticed, that is until they cause problems. Exposed in countries where it is warmer, nails are more visible, but for us, in the UK, the majority of feet are covered up. I have limited this article to the subject of thick nails associated with medical problems. Yuck, you might say…

WARNING!!!

This article carries a warning. Some pictures might be less appealing (but there is no flash photography) but the subject may not be for all consumers! If you have a thick nail problem or want to be intrigued by conditions of the nail, then do read on…

You might wonder what the point of toenails are, not least why they cause problems? These densely packed cells make up a flat structure that sits at the end of the toe over a bone called a phalanx and is exposed to pressure. Now if you had an impressive horn like our rhino, maybe it would make sense as a weapon. The nail might act as a deterrent if pointed, and as a child aged 7 I still can recall the burning pain caused when I upset a girl my own age as she raked my nose with her sharp nails!  Otherwise, as a piece of flat nail, it seems pointless. 

Growth

 

Figure 1. Cross-section of toe and nail on top of the phalanx (bone)

Nail growth is slow at around 0.1mm a day and is exposed to damage along its sensitive ‘growth cells’ called the matrix (diagram, Figure 1). The matrix is shown in red but the cells to in the lunula area are sensitive to damage. The name lunula comes from its half-moon shape and is coloured white. The latter part of the nail bed sits at the tip or edge of the nail. The end of the toe which contacts the shoe is the hyponychium. The attachment is sensitive to damage and if you like me have wrenched a fingernail, you will understand how uncomfortable this is.

Early damage in childhood

Many of us, and yes again that includes me, have a damaged the little toenail (no.5). This often comes four first shoes fitted when the nail was soft and easily compressed in early childhood. At this age, once directly impacted by tight shoes will lead to permanent. Yes, you’ve guessed it that happened to me. Sixty years ago my parents were less wise about this type of danger and yet took all other precautions. Put your children in soft shoes when they first start to walk.

As we age, nails are more resistant but significant damage, often from sports or activity in poor fitting shoe designs can lead to damage.

Clinicians talk about case histories, a diarised form of story telling covering the progress of a condition and how it was managed. As podiatrists, we concentrate on nail health and prevent tissue damage and pain. 

 

You can read my post on footwear fitting, click here

Case History: the damaged nail

Figure 2a (Left) and 2b (right)

What happens when a nail is damaged?

After a sixty-minute walk in light trainer type shoes, the fourth toenail of a man appeared dark where before it was clear. He reasoned this was the cause of his pain and indeed it was (Figure 2a). The nail is a solid structure made from three distinct layers to look like one. The third toe and nail are normal but the darkness seen with the 4th toenail is blood under the nail. This is called a haematoma, or a blood pool which goes hard.

The simple act of walking 3 miles allowed the toe to piston back and forward in the shoe, tearing micro blood vessels between the nail and softer nail bed. Podiatrists call this a sub-ungual haematoma. Ungual infers related to a nail. The study of nails is ‘onychology’ and accounts for a fair part of a podiatrist and dermatologist’s educational curricula. Five months later the nail looked as it does in (Figure 2b). The nail had distorted creating a thicker roof and even separating. With careful trimming, the nail settled with new growth. The outcome was fine and the learning is that nail damage does not always have to be permanent. And yet a child with tight shoes can have a permanent deformity. Repetitive damage is the key and that is what shoes can provide for the unwary. 

As a young podiatrist, I was taught to inspect nails for damage to the nail bed and to do this one had to ruthlessly cut back the armour plating. Patients did not always like the appearance afterwards but it was the only way to deal with badly deformed nails, that if left would become troublesome.

Damage under the nail could lead to ulcers and infection

I treated a lovely lady for many years passed on to me by her cancer specialist (oncologist) who would not let anyone other than me deal with her. The cancer drugs damaged her nails and in the early stages, the drugs used put her at risk from poor healing. Her nails were deformed, discoloured and separated so a large cavern appeared causing a build up of soft debris.

Podiatry is not about cosmetic nail care

The thick nail and medical health

Nails are an indicator of health. Podiatrists and doctors are taught to examine hands for a number of features that affect health. Nails are part of the examination. Here are a couple of the obvious ones.

Lungs and heart

The colour of the nail bed can appear rounded or clubbed. The blue dark nail bed shows poor circulation and the club shape is distinct as a  humped abnormal looking shape. This emphasises the likelihood of lung or heart disease. Flecks of dark red, called splinter haemorrhages, are another sign of heart disease and dark yellow discolouration may be associated with kidney disease.

Skin conditions

The colour of the nail bed changes. Dense white colour with a distorted nail may be due to psoriasis, but more often it is the little pits found on the nail that form and give away the cause.

Pigmentation within the nail requires expert attention and the rarity of many conditions can even fox medical doctors. The need for speciality clinicians has never been more important because the conditions of the past are no longer common and experience comes from exposure to many conditions during training. Education is more important than ever.

Cancer

A dark streak may look innocent but nail cancer (melanoma) can be overlooked and a sample is often used to rule out any concern. When a lady presented to my clinic she simply said ‘my nail has grown funny’. She had no nail and the skin was abnormal and the wrong red. I took a biopsy and as suspected she had skin cancer. This was easy enough to deal with and was not fatal as in melanoma which seems to be making a greater appearance. Fortunately, I have only lost one patient in his seventies to melanoma cancer in 40 years.

Iron deficiency and other shape changes

The thickness of nails may be due to disease and infection.  Iron deficiency can show up where the nail has a spoon-shaped appearance and named koiloynchia.

The commonest cause of nail problems stem from repetitive damage seen in my case history stories. The nail can remain thickened and even ridged. Once damaged the chance of fungal infection making an appearance increases because the three layers can be split open and the spores settle nicely in the warm, dark, moist environment. A fungal infection or onychomycosis does not look pleasant and once established in toes is difficult to treat. The group most likely to be affected are chronic smokers, older patients, those with repeated nail damage and groups who cannot care for themselves. The latter group are an important component of society relating to mental disease and senility.

From rhino to ram

Figure 3 a & b

Occasionally patients come with bad habits and destroy nails through picking (onychotillomania). The nail can shrink with thickness or can form cracks and distortions. The most impressive of all nails are those associated with the shape of a ram’s horn and are actually called rams horn nails. The figures above are rather self-evident.

The nail has a series of ridges better known in medical circles as onychogryphosis. Management is rewarding and after 20 minutes a nail can be made to look presentable. Although rarer today these are satisfying to treat because most medical doctors would be shocked at the appearance, let alone know where to start. The temptation might even be to ask the vet to look!

Having taught a module on onychology, not to be confused with oncology (cancer speciality) the ingrowing toenail, the fifth commonest referral from the GP is often of more interest. Some nails affect mobility to the point of disability and this is why in old age that foot health care is provided for all when required. With the sad loss of funding in the NHS for elderly foot health care, many have to turn to private means and often non-podiatrists are employed. While this might be fine for nails that you or I could cut as laypeople, the more difficult nails need specialist care and training.

If you dare to look, I have added an additional part to this article. If not switch off now. I should add that you cannot manage nails with the nail clippers shown in the adds with the type of nails shown or discussed in my article.

And to round off… Dr Nail Fan Club

If you want to see the type of problems confronting a podiatrist this absolutely naff ‘YouTube’ video provides plenty of imagery. Click here on the  Dr Nail Fan Club, but be warned, it is pretty grim and full of good old American US advertising. It actually shows some pretty nasty nails, but it is a short video (under 3 minutes) so not too long. This video does portray the nail problem well. However, unless you want to fly the States you can find help nearer to home with perhaps a little less ‘in your face’ promotion.

Look out for an article later this year on the ingrown toenail. And do ‘sign up’ to stay in touch

Thanks for reading ‘What do rhinos and rams have in common with feet?’ written by David Tollafield.