Nail Disorders & their significance

Nails have functional and aesthetic importance for patients. Toe nail disorders are common and often seen as minor ailments. If pain free, they can be long tolerated by sufferers slow to seek their identification and treatment. Ultimately many attend GP clinics or A&E nurses, with a variable response due to lack of expertise in dealing with the most distal parts of the body. Others seek podiatric help. The significance of nail lesions varies from minor concern to serious manifestation of sinister potential. They can testify to dietary or hormonal deficiency, herald generalised disease, and signal a possible fatal outcome. Almost always, nail disorders are diagnosed on the basis of clinical findings, but further general medical investigation and imaging methods such as ultrasound may be required for accurate assessment.1 Often a localised discomfort associated with one toe-nail, all the toenails and surrounding tissue can be affected.

Iain McIntosh

Nail conditions can be caused by malnutrition, localised and systemic infection, neoplasia and trauma. Some are more likely to affect the young, or the elderly. In elderly people carers can fail to appreciate that toe nail diseases can interfere with locomotion, disturb normal walking and result in patients going “off their feet” and becoming chair bound. Residents in care homes in particular are at risk of having toe nail disorders neglected by untrained, uncaring or over-worked staff2 .

The podiatrist, familiar with maladies of the feet, can often make a speedy diagnosis of toe nail afflictions and institute treatment, when a characteristic lesion is presented. Some conflicting conditions have common features however, making diagnostic decisions more difficult. Careful observation of the affected nails in regard to thickness, colour, texture, shape and surface can simplify identification. Taking a good clinical history is essential as well as close attention to proximal and general skin status. Some conditions resort to appropriate therapy, others will be untreatable and some will require referral to a physician or dermatologist.3

Nail Thickness

Nail growth density decreases with age, by up to one third from youth to old age. Over time, nails become thin and brittle with a lustreless grey surface and darker band, so-called “half-and-half nails” in which the proximal part of the nail is grey and the distal part brown. This half-andhalf appearance can often also occur in people with uraemia (a toxic condition resulting from kidney disease in which there is retention in the bloodstream of waste products normally excreted in the urine) and after chemotherapy discussed later as when there is defective keratinisation due to cell arrest in the nail.

Nails in a normal person have subtle longitudinal ridges, a feature becoming more accentuated with advancing years. In the individual older person, the nail can have a strikingly beaded appearance which is not pathological. A ridging disorder of all, or many, of finger and toenails can however occur, primarily in children or adolescents. It is an excessive ridging of the nail plate referred to as “rough nails” or trachyonychia. (Severe dystrophy caused by extensive involvement of the matrix) Also known as “Twenty nail dystrophy,” the nail plate flattens and the lunula is spotted, or obscured. The condition is sometimes seen in patients with lichen planus and psoriasis and the aetiology is unknown. In chronic paronychia, often seen in women who are cooks, nurses or florists who have hands often immersed in water, the matrix of the nail can be involved causing characteristic transverse ridging of the nail plate.4 Beau’s lines, or horizontal ridges on the nails, have been related to malnutrition, heart attack, infections, and diabetes.5 Repetitive trauma to the nail bed can bring considerable permanent thickening of the nail if it has been lost and regrows.

Nail Status

Coloured nails

Marked colour changes in the nail can help identify the underlying condition.6

White nails (Leuchonychia - white nails or white

spots on the nails) is a common discolouration of the nails. It may be traumatic in origin due to upset keratinisation when the nail has been formed, but it also can be congenital. Transverse white lines can also be caused by hypo-albuminaemia seen in patients with cirrhosis of the liver and also in patients having cancer systemic chemotherapy. Black nails can be caused by the pigment from pseudomonas infection and after subungual haemorrhage following trauma. Some forms of systemic chemotherapy can result in black or

brown discolouration of nails, with the colour change caused by increased melanin formation in the matrix.

Red nails or red lunulae are rare, with the purplish-red colour caused by hyperaemia of the nail bed. It occurs in systemic lupus erythematosus and in alopecia areata (an autoimmune condition) Blue nails, where there azure blue lunulae is a manifestation of argyria, with the change permanent and eventually deep in colour. Argyria or argyosis is a condition caused by excessive exposure to chemical compounds of the element silver, or to silver dust. The silver particles accumulate in the skin tissue.

Yellow nails. A yellow colour appears in nails when they stop growing. Patients with yellow nail syndrome need to cut the nails very infrequently. There is a yellowish green discolouration of the nail plate, which is thickened and the surface is smooth and carved in both axes. The cause is obscure, but the discolouration has been associated with pulmonary infections. As noted previously in “halfand-half nails” the proximal part of the nail is white and the distal part is brown. A yellow colouring with nail destruction can also occur with chronic fungal infection of the nails.7 Half-and-half nails” are also sometimes seen in patients with AIDS

Nail shape

Ingrowing toenails are common with deformity of the nail due to ill-fitting footwear and over trimming of the lateral edges of the nails. Coagulation tissue formed at the lateral nail border confirms the diagnosis.3 Pincer nails are also known as “trumpet nails” with transverse over curvature of the nails. This can be hereditary or due to trauma such as unremitting pleasure from ill-fitting footwear and can occur where the person has psoriasis. Clubbing of the nails is a well-recognised skin marker of associated systemic disease. It can accompany chronic lung problems, or heart disease with cor pulmonale and with carcinoma of the lung. Familial clubbing not associated with disease is also quite common and a history of familial clubbing should be elucidated to exclude this possibility.8 Spoon nails (koilonychias) occur where the nail plate is very brittle, thin and flattened with slightly elevated edges. They can be hereditary and sometimes

REFERENCES

1 Aluja J F,Quiasúa M Nail unit ultrasound: a complete guide of nail diseases. J Ultrasound.2017 20(3):181-192 2 McIntosh IB The vulnerable ageing foot Geriatric Medicine, 12-15, 2014 3 McIntosh IB Identification and management of nail and toe disorders Podiatry Review 72 (6), 14-16, 2015 4 Guidozzi F Foot problems in older women Climacteric.2017: Sept 1-4 5 McIntosh IB managing the diabetic foot Podiatry Review 72 (5), 17-21, 2015 6 Thomsen K Nails .A manual and atlas AO print Copenhagen Denmark 7 McIntosh IB Fungal infections of the feet Podiatry Review 71 (1), 8-10, 2014Podiatry Review 72 (6), 14-16, 2015 8 Medicine Ed Souhami R Moxham 1994 Churchill Livingstone 9 Gaziano R, Galluzzo New insight into the pathogenesis of nail psoriasis and overview of treatment strategies.Drug Des Devel Ther. 2017 Aug 30;11:2527-2535. occurs in the big toenails of children below two years of age. It can also be acquired where there is malnutrition, and iron deficiency and with scleroderma. 8.

Pterygium inversum is usually seen in systemic scleroderma and with systemic lupus erythematosus. It is fixation of the distal part of the nail bed to the underside of the distal part of the nail plate. This can result in over curvature of the nail. Due to the tenderness which results, patients hesitate to cut the nails and wear them long. Lupus erythematosus vasculitis in the nail bed can also give rise to onycholysis. 8 Systemic and localised diseases can affect the nails. A characteristic feature of psoriasis of the nails is onycholysis with a yellowish brownish hue resembling that of an oil spot and caused by elevation of the nail plate by a psoriatic plaque in the nail bed. Pitting of the nail plate is seen with psoriasis and in alopecia areata and severe hand eczema.9 In 10% of patients with lichen planus the nails are involved. The nail plate is thinned, with longitudinal ridges becoming very fragile and sometime koilonychias may even develop. Lichen planus of the nails may ultimately lead to complete nail atrophy and it sometimes manifests itself as 20 nail dystrophy 8 Pityriasis rubra is a rare disabling skin disease which has an effect on the nails which is thickened and there is onycholysis with severe subungual hyperkeratosis and nail splintering. Chemotherapy effects Multiple transverse white bands occur corresponding to a chemotherapeutic cycle. Inspection of the nail will reveal the number of cycles given. The white colouration is caused by defective keratinisation to cell arrest in the matrix. Chemotherapy may produce Beau’s lines. Pulse therapy with corticosteroids can also produce dark bands on the nail.6

Summary

Abnormal nail formation is often tolerated by sufferers who delay in seeking treatment. Nail disorders in elderly people in particular may be disregarded or their significance unappreciated by health professionals, especially in the care home environment. Careful observation of the nail and the surrounding tissues is paramount. Nail shape, thickness, colour, fragility and density are crucial considerations aiding accurate diagnosis. Clinical acumen, good history taking, acute observation of the toes and surrounding tissues can identify the condition and with accurate diagnosis, appropriate remedial action can be taken. This may mean conventional podiatric care, treatment of a localised infection, referral for systemic therapy or further investigation by dermatologist, or physician.