Clubbing refers to nails with increased longitudinal curvature and loss of angle between the nail bed and fold, thickening of the finger ends and fluctuation of nail beds.
It is slow to develop and may be a marker of internal disease, such as COPD, carcinoma of the lung, or cor pulmonale. It may also be idiopathic, which can be familial and presents in younger patients.
Where it is noticed for the first time in older patients, especially smokers, investigation for an underlying cause is advisable.
Leuconychia, in which the nails become white, is a common finding and bears no relation to calcium levels. The cause is often unknown but it may be a result of trauma.
In almost all cases, patients can be reassured and no further investigations are required.
Recurrent multiple transverse white lines (Muehrcke's lines) are caused by hypoalbuminaemia and associated with cirrhosis of the liver. If this is suspected, further investigations are advisable.
It is common for nails to become thicker and harder with increasing age. This, along with decreased mobility and joint pain, can make them more difficult to cut. When left, such nails can become very dystrophic and unsightly, producing the condition known as onychogryphosis.
In at-risk patients, such as those with diabetes or peripheral vascular disease, referral to podiatry and appropriate patient education is essential and may reduce the risk of potentially serious complications.
This localised inflammatory reaction is caused by piercing of adjacent skin by the lateral nail edge. Causes include poorly fitting footwear, poor pedicure and trauma. Secondary infection is common, leading to pain and a purulent discharge. Soaking the foot regularly in warm saline and avoiding trauma, with simple procedures such as cutting the nail straight across and pressing cotton wool under the distal end of the nail, to lift it away from the nail bed, may help. In chronic cases, podiatric surgery may be required.
Habitual biting or repeated trauma to the fingernails is very common. Where the nails are bitten repeatedly, the exposed hyponychium forms a swelling at the tip, giving the finger a typical appearance. In other cases, repeated trauma to the proximal and lateral nail folds will affect the growing nail. Repeated trauma to the middle part of the proximal nail fold (shown here) is called median nail dystrophy. In all cases, reassurance can be given that there is no underlying pathology.
Onycholysis refers to the condition in which the nail plate separates from the nail bed, producing a white or lighter discoloration beneath the nail. In almost all cases, it starts at the distal end of the nail and extends proximally. It may affect a single nail or all nails of the hands and feet. In most patients, the cause is idiopathic, but it may be associated with conditions such as a fungal infection, trauma, psoriasis, thyrotoxicosis and some drugs. It can be difficult to treat.
- Dr Stollery is a GP in Kibworth, Leicestershire, and clinical assistant in dermatology, Leicester Royal Infirmary.