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AD_ 0 3 3 _ _ _ OCT 3 1 _ 0 8 . P DF Pa ge 1 1 0 / 2 3 / 0 8 , 3 : 1 1 PM How to treat Pull-out section w w w. a u s t r a l i a n d o c t o r. c o m . a u Complete How to Treat quizzes online (www.australiandoctor.com.au/cpd) to earn CPD or PDP points. inside Onychomycosis Common non-fungal nail disorders Nails in systemic disease Nail trauma and tumours Ingrown toenails The authors DR MARGUERITE BYRNE, dermatology registrar, St Vincent’s Hospital, Fitzroy, Victoria. DR ANNE HOWARD, head of dermatology, Western Hospital, Footscray; and consultant dermatologist, nail clinic, Skin and Cancer Foundation, Carlton, Victoria. Common nail DISORDERS Introduction HUMAN nails are important for protection, dexterity and fine touch. Smooth, lustrous nails are seen as an aesthetic adornment, and nail disease can be socially embarrassing for some patients. Nail disease is very common and is of significant concern to patients. Recognising nail changes is essential for accurate diagnosis and treatment of local nail disease and for the appropriate investigation into systemic illnesses (see table 1, page 35). Nail structure and function Normal nail structure consists of the nail matrix, the nail bed, the proximal and lateral nail folds, the cuticle and the nail plate (figure 1, page 35). The nail plate is formed by the nail matrix which is made up of germinal epithelium. The nail matrix lies underneath the proximal nail fold and only the most distal portion, the lunula, is visible. The nail matrix is protected from the environment by the cuticle, www.australiandoctor.com.au which makes a waterproof seal under the proximal nail fold. The cuticle can be damaged by being cut or pushed back during manicures or by repeated trauma through picking and biting. This may result in damage to the nail matrix and subsequent nail plate changes. cont’d page 35 31 October 2008 | Australian Doctor | 33 AD_ 0 3 5 _ _ _ OCT 3 1 _ 0 8 . P DF from page 33 Another important structure in nail development is the terminal phalangeal bone. The nail matrix lies close to the bony segment and the bone is important in forming the nail shape. Changes to the bone or joint can lead to distortion in the nail plate, as in pincer nails. The nail plate lies on the nail bed. The under-surface of the nail plate has longitu- Pa ge 1 1 0 / 2 3 / 0 8 , dinal folds that interdigitate with corresponding grooves on the nail bed, resulting in firm adhesion. Trauma by manicuring instruments, in an attempt to clean under the nail, and infections can lead to separation of the nail plate from the nail bed (onycholysis). Unlike bones, nail-plate hardness is not dependent on calcium levels. Rigidity of the nail plate is due to hard ker- 3 : 1 2 PM atins, which contain a large amount of sulphur bonds. Another essential component for healthy nails is water. Water is essential to improve flexibility in the nail plate and to decrease brittleness. Fingernails grow on average at a rate of 0.1mm/day, with about two months required for the nail to expose itself from underneath the proximal nail fold. Toenails grow at half this speed. Onychomycosis FUNGAL infections of the nail affect 2-8% of the general population and about 22% of people in Australian nursing homes. It is usually the toenails that are affected. Causes Most cases of onychomycosis are due to infection with the dermatophytes Trichophyton rubrum and Trichophyton mentagrophytes var interdigitale. Immunosuppressed people are at higher risk of infection. Repeated microtrauma and occlusive footwear are common predisposing factors. Classification Onychomycosis is classified according to the site of infection. Figure 1. Normal anatomy of the nail. Distal and lateral onychomycosis Nail plate Nail bed Nail plate This is the most common form of onychomycosis. Infection begins usually at the distal part of the nail and extends in a subungual direction. This causes the distal subungual hyperkeratosis, onycholysis and brownish discolouration of subungual debris. White or yellow streaks or spears travelling proximally may help in differentiating subungual thickening of onychomycosis from trauma and psoriasis. Superficial white onychomycosis Nail fold Nail matrix The most common causative organism is T mentagrophytes var interdigitale, which invades the surface of the dorsum of the nail. This leads to a superficial, chalky white plaque with distinct borders. It can be treated by simple curettage of the white plaque on the nail. Proximal subungual onychomycosis Lunula (top part of matrix showing through nail) This pattern of onychomycosis occurs when the pathogen gains entry to the nail bed and nail plate through the proximal nail fold and cuticle area. Proximal subungual onychomycosis is usually found in patients with HIV and other immunocompromised patients. Total dystrophic onychomycosis This is probably an advanced form of distal subungual onychomycosis. The entire nail becomes affected and appears thickened, opaque and yellow-brown. Table 1: Differential diagnoses of nail signs Sign Conditions Sign Conditions Nail thickening (distal subungual hyperkeratosis) Tinea Trauma Psoriasis Developmental Clubbing Nail thinning Trauma Brittle nails Lichen planus Impaired circulation Twenty-nail dystrophy Hereditary Chronic lung infections Pulmonary malignancy Cardiac abnormalities Cirrhosis Inflammatory bowel disease Pitting Longitudinal grooves Horizontal grooves Koilonychia Nail destruction Trauma Psoriasis Photosensitivity Hyperthyroidism Hereditary Racial Trauma Drugs: minocycline Vitamin B12 deficiency Longitudinal melanonychia: — naevi — melanoma Psoriasis Eczema Alopecia areata Reiter’s syndrome Yellow Ageing (multiple) Myxoid cyst Angiofibroma Median-nail dystrophy Yellow nail syndrome Fungal infections Cigarettes Drugs: tetracycline, lithium White Cirrhosis Hypoalbuminaemia Chemotherapy Uraemia Malignancy – lymphoma Trauma Trauma Beau’s lines Raynaud’s disease Chemotherapy Hereditary Juvenile Iron-deficiency anaemia Haemochromatosis Raynaud's disease, SLE Trauma Bowen’s disease Squamous cell carcinoma Melanoma Lichen planus Green Red Blue Many conditions mimic onychomycosis. For this reason it is important to make an accurate diagnosis. Unfortunately, when using fungal microscopy and culture, a false-negative result occurs in about 40% of cases. When sending a specimen for microscopy and culture as much subungual material as possible should be clipped from the distal nail to maximise the yield. Clippings can also be sent for histopathology to assess for hyphae in the nail plate. Treatment Discolouration of the nail plate Black/brown Onycholysis Diagnosis Pseudomonas infection Aspergillus infection Polycythaemia Carbon monoxide poisoning Cardiac insufficiency Tumours (glomus) Drugs: antimalarials Argyria (silver deposits due to consuming silver or from industrial exposure) No treatment apart from regular nail clipping is an option. Oral therapy is usually necessary to cure infections in the nail plate. Oral agents include the following. Terbinafine (Lamisil) Terbinafine is the treatment of choice for onychomycosis due to dermatophytes in Australia. It is subsidised by the PBS for microbiologically proven dermatophyte infection. The dose is 250mg daily, with a quantity of 42 tablets supplied and one repeat. In our nail clinic we often ask patients to take the second course of 42 tablets at a dose of one tablet twice a week. This prolongs the therapy and still gives a reasonable dose in the nail plate. It is important to stress to patients that infected toenails need to grow out, which can take up to one year. Side effects are normally minimal, but agranulocytosis and liver function abnormalities have been reported. A white cell count and liver function tests are recommended after one month of treatment. Itraconazole (Sporanox) Itraconazole is also highly effective. It is often given as ‘pulse therapy’, two tablets twice daily (ie, 400mg daily) for the first week of each month, for three months of therapy. Fluconazole Fluconazole at a dose of 150mg orally once a week for three months is used extensively overseas. It is expensive for patients in Australia, as it is not covered by the PBS. Griseofulvin Two 500mg tablets daily of griseofulvin are usually required to achieve sufficient dosage in the nail. As this drug is only fungistatic, prolonged treatment for up to two years may be needed for toenails, especially in the elderly. The cure rate is around 50% and relapse is common. Nausea and headaches may occur. Liver function tests should be monitored with cont’d next page www.australiandoctor.com.au 31 October 2008 | Australian Doctor | 35 AD_ 0 3 6 _ _ _ OCT 3 1 _ 0 8 . P DF Pa ge 1 1 0 / 2 3 / 0 8 , 3 : 1 2 PM How to treat – common nail disorders from previous page Onychomycosis with total dystrophy. long-term therapy. Ketoconazole Ketoconazole can be effective in the treatment of onychomycosis, but its use is inadvisable because of potential liver toxicity. Topical therapy For superficial white onychomycosis or limited disease, topical treatment can be useful, especially in conjunction with removal of diseased nail. Amorolfine (Loceryl) is the most effective topical agent currently available in Australia. It is a paint applied weekly after rubbing the nail plate with a file. Physical treatment Nail removal, surgically or with 40% urea paste, can be helpful, especially in single-nail disease. It is usually advisable to use topical or oral antifungal treatment as well or the disease may recur. Common non-fungal nail disorders Psoriasis INVOLVEMENT of the fingernails and toenails is reported in 50% of patients with psoriasis. The fingernails are more commonly affected than the toenails. Clinical features of psoriasis are given in table 2. Dermatophyte infection can often mimic psoriasis and is important to exclude. A few points may be helpful to differentiate the two. In psoriasis often all the nails will eventually become involved, whereas this is less common for fungal infections. Psoriatic nails may spontaneously resolve, whereas this is not the case for fungal infections. In addition, the fingernails are frequently involved in psoriasis, whereas fingernail involvement is less common in fungal infections. Investigation Distal nail clippings sent for histopathology can be useful to show parakeratosis on the nail plate in psoriasis. Nail clippings and scrapings of subungual debris should be sent for testing to exclude onychomycosis. Management Psoriasis of the nails is difficult to treat and many patients opt for no treatment at all. Management options are listed in table 3. Onycholysis This occurs when the distal nail bed is separated from the nail plate. It occurs in psoriasis, thyroid disease and many other conditions, but in a large number of cases the cause is not identified. Acute trauma can initiate it, and repeated minor trauma with secondary infection can perpetuate the problem, ie, toenails rubbing on shoes or repeated manicures. Some drugs, including tetracyclines, can also cause photo-onycholysis. The space caused by the separation gathers dirt and debris. Often candida species can be cultured from the debris. Candida is rarely the cause of the problem but may prevent nail reattach- 36 Table 2: Clinical features of psoriasis Table 4: Management of onycholysis ■ Pitting ■ Discolouration of the nail ■ Onycholysis ■ Oil spot — a yellow/salmon discolouration in the nail bed resembling a drop of oil beneath the nail plate; the most diagnostic sign of nail psoriasis ■ Splinter haemorrhages ■ Subungual hyperkeratosis ■ Severe total nail dystrophy ■ Psoriasis around the nail fold on the finger Table 3: Management of psoriasis of the nails Physical ■ Advise the patient to keep the nails as short as possible. ■ Minimise trauma by advising the patient to: — improve footwear to avoid rubbing — not insert objects under the nail in an attempt to clean out debris — avoid artificial nails — wear gloves for housework and gardening. ■ The nail bed area should be dried several times a day with a hair dryer. This helps to control bacteria and yeast numbers. Psoriasis. Physical ■ Minimisation of trauma around the nail. Scraping under the nails and trimming the cuticle should be avoided as this can cause a Koebner phenomenon and exacerbate the disease Cosmetic ■ Mild forms of psoriasis often have sufficient keratin for adherence of varnish and artificial nails, which can help with cosmetic appearance Topical ■ Potent topical steroids (under occlusion) ■ Topical calcipotriol ■ Intralesional steroid injection. This involves injection into the nail matrix for severely dystrophic nails, or into the nail bed for onycholysis or subungual hyperkeratosis. Triamcinolone acetonide (Kenacort-A 10) 0.2-0.4mL diluted with equal parts of 1% or 2% Xylocaine without adrenaline can give several months of remission Onycholysis. PUVA ■ Oral and topical psoralens with UVA have been used extensively with varying success. Rarely used for nail problems alone Methotrexate ■ This is usually given orally at a dose of 10-15mg once weekly. It is usually prescribed for patients who have widespread skin or joint involvement as well. It is seldom used for nail involvement alone because it can take a long time to be effective and because of the potential severe side effects Onycholysis with secondary pseudomonas infection. Oral acitretin ■ Referral to a dermatologist is needed for this drug. It is seldom used for nails alone but it is useful in thinning of hyperkeratotic nails. Side effects are common, including mucocutaneous dryness, peeling of the palms and soles, muscle aches, fatigue, increased lipid levels and rarely liver toxicity Iontophoresis with dexamethasone ■ This is a new treatment which is performed weekly and is only available at some specialist treatment centres. It involves placing the hands into a specialised shallow bath with dexamethasone while a weak electrical current is run through the water. The dexamethasone is absorbed under the nail into the nail bed | Australian Doctor | 31 October 2008 ment. Pseudomonas or aspergillus colonisation can produce a green, blue or black discolouration. The fingernails are more Brittle nails. often involved than the toenails. If the toenails are affected it is important to exclude dermatophyte infection. The management of ony- www.australiandoctor.com.au cholysis is outlined in table 4. Brittle nails Many factors are associated with brittle nails but water Topical ■ Miconazole lotion or 15% sulphacetamide lotion can be applied under the nail plate daily to decrease contaminants. ■ If pseudomonas is present, white vinegar soaks for 10-20 minutes twice a day are recommended (10% white vinegar in water). ■ If Candida albicans is grown from the nail plate, oral treatment with ketoconazole, fluconazole or itraconazole can be very helpful. Three to six months of treatment is often needed. Liver function needs to be monitored, especially with ketoconazole. Terbinafine is of no use for this condition. is probably the most important. Repeated wetting and drying has been shown to weaken the nails. Chemicals, cement, detergents and alkalis also lead to dissolution of intercellular adhesive factors and thus to brittle nails. There are many systemic causes, including deficiencies in iron and vitamins A, C and B6, but these are rare. Calcium deficiency is not a cause of brittle nails. There is little calcium in the nail and it does not contribute to nail hardness. AD_ 0 3 7 _ _ _ OCT 3 1 _ 0 8 . P DF Clinical features of brittle nails include onychorrhexis (longitudinal ridging and fissuring of the nails) and onychoschizia (horizontal layering of the distal nail plate, rather like the split ends of hair). The treatment of brittle nails is outlined in table 5. Lichen planus Lichen planus is an inflammatory condition of the skin and/or mucous membranes. Nail involvement occurs in 10% of cases and occasionally the nails are involved without skin or mucous membrane features. Usually more than one nail is involved. Clinical features of lichen planus are given in table 6. Results of treatment are often disappointing but steroids may halt the scarring. Options are shown in table 7. Twenty-nail dystrophy This condition occurs in childhood and usually resolves spontaneously. The nails (usually all 20) are thin and rough. The aetiology is unclear but it is thought to be of an inflammatory nature. The condition usually improves with age over a 2-3-year period. Alopecia areata may also affect all 20 nails and is typically associated with rough, diffuse pitting. Pa ge 1 1 0 / 2 3 / 0 8 , 3 : 1 4 PM Table 5: Management of brittle nails Physical Advise the patient to avoid trauma, detergents and chemicals and to wear rubber gloves to avoid excessive hydration and subsequent drying out of the nails. Oral Oral biotin 2.5mg daily has been shown in some studies to help. One tablet twice daily of Blackmores Hair, Nails and Skin or Tricusil provides 2.5mg of biotin, the required daily amount. Topical Nail moisturisers such as 10% urea creams are probably better than nail hardeners. Alphahydroxy acids may also be effective eg, lactic acid, glycolic acid creams. Lichen planus. Table 6: Clinical features of lichen planus ■ Thin and rough nails ■ Atrophy ■ Longitudinal ridging ■ Transverse splitting ■ Scarring ■ Pterygium (a scar from the proximal nail fold that merges with the nail bed, eliminating the normal cuticle) ■ Complete loss of the nail Table 7: Management of lichen planus ■ Potent topical steroids (under occlusion) ■ Intralesional steroid injection ■ Oral prednisolone (short course) ■ PUVA ■ Oral retinoids Table 8: Management of chronic paronychia Twenty-nail dystrophy. Physical ■ Advise the patient to keep the hands out of soaps and detergents and wear gloves when possible ■ Also advise them to avoid trauma to the cuticle, and not to push back, cut or try to clean under the cuticle Other disease ■ Treat any contributing skin disease Topical ■ Miconazole solution may be applied twice daily to the space between the nail fold and nail plate ■ If the hands have to be immersed in water, nystatin ointment or petroleum jelly should be applied to the nail fold ■ Topical steroid ointment applied to the proximal nail folds has been shown to be the most effective treatment for this condition Chronic paronychia. fold and is most common in those who have their hands frequently in and out of water and detergents. The cuticle is damaged and the watertight seal Chronic paronychia Chronic paronychia is a chronic inflammatory condition of the proximal nail it usually makes with the nail plate is lost. A space is created between the nail fold and nail plate, allowing water and detergents to irritate and inflame the proximal nail fold. Candida species and bacteria are commonly cultured here and aggravate the condition. Skin disease affecting nail folds, such as psoriasis, eczema and perniosis, may also contribute. The management of chronic paronychia is outlined in table 8. Nails in systemic disease Koilonychia KOILONYCHIA is a nail dystrophy in which the nail plate becomes flattened and the edges evert. This gives the nails a concave or spoonshaped appearance. Although classically this condition is thought of in iron-deficiency anaemia, it is rarely due to a systemic cause and is more commonly idiopathic or caused by chemical trauma. It is seen in thin nails in the elderly and in patients with peripheral vascular disease and is a physiological variant in children. Clubbing Clubbing is a well-known sign in which there is an increase in the transverse and longitudinal curva- Koilonychia. ture of the nail. There is also hypertrophy of the pulp of the digits. This condition usually affects all 20 digits and can be congenital. Any acquired clubbing is suspicious and the patient needs to be investigated thoroughly for causes. These include pulmonary disease, especially chronic infections and cancers, cardiovascular disorders, bowel disease, Graves’ disease and SLE. appear 4-8 weeks after the acute illness. In severe cases the nail plate can be completely divided and the nail eventually shed (onychomadesis). Systemic causes for Beau’s lines usually affect all 20 nails. If only one nail is affected, trauma is the likely cause. Beau’s lines Splinter haemorrhages These are transverse depressions that extend from one lateral edge to the other. They are due to disruption in matrical activity resulting in focal thinning of the nail plate. This can occur with any severe acute illness, particularly febrile illnesses, in the postnatal period, and can also be caused by drugs (cytotoxic). Classically the transverse grooves Splinter haemorrhages are longitudinal haemorrhages from fine capillaries in the nail bed. They occur between dermal ridges and give a characteristic plum/brown/black splinter appearance, depending on age. The most common cause for splinter haemorrhages is trauma, particularly if it occurs in a single digit. Multiple splinter haemorrhages should raise suspicion of systemic causes including infections (endocarditis), vasculitis, arterial emboli, antiphospholipid syndrome, SLE and psoriasis. Yellow nail syndrome This is a rare syndrome with the triad of thickened yellow fingernails and toenails, lymphoedema and infective respiratory disease. The nails are slow growing, hypercurved laterally and longitudinally, and onycholytic, with no cuticle. The respiratory disease needs to be treated and sometimes this improves nails. Vitamin E 6001200 IU/day has been helpful in some cases. Trauma-induced nail dystrophy NAIL trauma is one of the most common causes of nail dystrophy. Repeated trauma is common from shoes and sports such as jogging, netball and football. Changes to the underlying bones and joints with arthritis and ageing can exaggerate the problem. Often toenails respond to trauma by thickening, which may lead to the misdiagnosis of fungal infection. Onychogryphosis This is most common in the great toenail. The entire nail plate becomes thickened and opaque. In the extreme form it can look like a ram’s horn or snail shell or begin to spiral. It is seen in elderly patients secondary to pressure from footwear and biomechanical factors. Deformities of the feet such as hallux valgus are commonly associated with this condition. Early onychogryphosis. The nails are thick to cut and the patient may benefit from consultation with a podiatrist for filing and protection of the nails from Pincer nails. mechanical rubbing in shoes. Pincer nails Pincer nails are a trans- www.australiandoctor.com.au verse over-curvature of the nail plate particularly at the free edge. As the nail grows the lateral edges of the nail compress the distal nail bed. Constriction of the nail pulp can eventually become painful and lead to an ingrown toenail. The condition is commonly caused by degenerative osteoarthritis of the distal interphalangeal joints and enlarging of the bone secondary to osteophytes. This enlargement of the joint causes widening at the base of the nail and subsequently leads to a conical-shaped nail plate. If the pincer nail is not painful or constricting, keeping the nails short and seeing a podiatrist may be enough. Lateral matrix ablation is a possible treatment for more severe pincer nail deformity. 31 October 2008 | Australian Doctor | 37 AD_ 0 3 8 _ _ _ OCT 3 1 _ 0 8 . P DF Pa ge 1 1 0 / 2 3 / 0 8 , 3 : 1 4 PM How to treat – common nail disorders Nail tumours Key points ■ Periungal fibroma Table 9: Causes of longitudinal melanonychia THESE are benign skin-coloured tumours that are elongated, usually with a narrow base and hyperkeratotic tip. They arise in the periungual area and grow out along the nail. This causes pressure on the nail matrix and results in a longitudinal groove in the nail plate. They can occur spontaneously, but trauma has also been implicated. Surgical excision is usually curative. ■ Glomus. Glomus tumour These are rare tumours arising from the neuromyoarterial glomus bodies that regulate blood flow in the skin. They present as a small blue-red focus in the nail bed. Nail changes depend on the location of the tumour. The nail plate may be distorted by pressure of the tumour on the nail plate and distal splitting of the nail can occur. Glomus tumours are particularly painful in cold temperatures and with changes in pressure. They are usually benign, solitary and more common in women. MRI of the nail will usually detect most glomus tumours. Treatment is by surgical excision. Table 10: Features that should raise suspicion of melanoma A — Age, with peak incidence in the fifth to seventh decades B — Brownish-black band with breadth >3mm Myxoid cyst. E — Extension of the brownish-black pigment of the nail bed, nail matrix, and nail plate onto the adjacent cuticle and proximal and/or lateral nail folds (Hutchinson’s sign) F — Family history Bowen’s disease. warts persistent. Cryotherapy may damage the nail matrix. Wart paints, particularly those that are immunestimulating, are the most successful treatments. Longitudinal melanonychia. Squamous cell carcinoma in situ is an intraepithelial neoplasm common in the skin, but it can also occur around the nail. It usually presents as a warty plaque in the lateral nail fold. It usually involves one nail, but can be polydactylous. An association with oncogenic papilloma virus has been shown in some cases. A biopsy should be taken for diagnosis and the treatment is surgical excision. Mohs’ surgery, to conserve normal tissue, is particularly helpful. It may progress to squamous cell carcinoma. Melanoma Biopsy of a longitudinal melanonychia. Most melanomas occur on a single digit in adult life, most commonly on the thumb, index finger and great toe. Melanomas in the nail matrix usually appear as a longitudinal black or brown streak. 38 | Australian Doctor | 31 October 2008 There are many causes of longitudinal melanonychia, including trauma, drugs and naevi, but the most sinister cause is melanoma (table 9). Longitudinal melanonychia is caused by increased melanin synthesis by melanocytes in the nail matrix, leading to a brown or black longitudinal streak in the nail plate. Acral lentiginous melanoma is the most important diagnosis to consider and makes up 2-3% of all melanomas in the white population and 15-20% of melanomas in the black population. Because of late diagnosis the prognosis for this melanoma is very poor, with average five-year survival of less than 50%. Features that should raise suspicion of melanoma are outlined in table 10. Management A biopsy is required in all suspicious cases. Any adult patient with longitudinal melanonychia of a single nail that is not clearly related to a definitive cause should undergo at least a nail matrix punch biopsy. This is done by reflecting the proximal nail fold and using a 3mm punch to biopsy the most proximal portion of the streak. The proximal nail plate is relatively thin and the punch can be performed through the nail plate. Taking a 3mm punch is less likely to result in permanent nail dystrophy than a biopsy involving a larger specimen. If melanoma is confirmed, treatment depends on its thickness. Insitu melanomas may be able to be treated with removal of the nail apparatus, but invasive tumours usually need amputation of the distal phalangeal bone. Prognosis is poor. Ingrown toenail. www.australiandoctor.com.au ■ ■ ■ Ingrown toenails (unguis incarnatus) THIS is a very common and painful complaint commonly affecting the great toe. The lateral nail plate grows into and penetrates the lateral nail fold causing irritation and inflammation. The cause is usually multifactorial and includes poorly fitting footwear, infection, incorrectly trimmed toenails and trauma. It can also be caused by a hereditary imbalance between the width of the nail matrix and the nail bed and by oral retinoids. Management in early disease is usually conservative. This includes soaking the foot in warm water, use of topical or oral antibiotics, a proper nail-trimming technique, appropriate footwear and elevation of the corner of the nail. If the ingrown toenail is more severe with significant pain, infection or lateral wall hypertrophy, this is best treated with partial nail avulsion, lateral matricectomy and destruction of the lateral wall granulation tissue. ■ Assessing longitudinal melanonychia Bowen’s disease Warts Warts are common on the hands and periungual area. Caused by HPV infection, they present with papillomatous lesions of the nail fold. They may be tender and multiple, and spread by biting and picking the nail. Warts do not usually cause destruction of the nail; if destruction is present a malignancy should be suspected. Treatment can be difficult and C — Change in morphology: darkening of the band; widening of the linear streak, with blurring of the borders D — Digit that is involved (thumb > great toe > index finger) Myxoid pseudocyst of digits These are firm cystic lesions containing gelatinous fluid that arise between the proximal nail fold and the distal interphalangeal joint. They are believed to be periarticular degenerative lesions and can be associated with osteoarthritis. They are usually asymptomatic and more common in fingernails than toenails. Enlargement of the cyst can compress the nail matrix and cause a longitudinal depression. Diagnosis can usually be made clinically but investigation with ultrasound may be helpful in differentiating the cyst from surrounding structures. Incision and drainage of the lesion will express the fluid, but recurrence is common. Surgical excision and ablation of the tract leading into the joint is the most effective treatment and usually curative. Racial variation Trauma ■ Pregnancy ■ Naevi ■ Melanoma ■ Systemic causes (eg, hyperthyroidism, Addison’s disease, etc) ■ Fungal infections ■ Drugs (cytotoxins) ■ Syndrome association (eg, Peutz-Jeghers syndrome) ■ New-onset longitudinal melanonychia in a white-skinned patient, or sudden darkening or widening of longitudinal melanonychia in a darker-skinned patient warrants a biopsy. Periungual extension of the pigment onto the proximal or lateral nail fold (Hutchinson’s sign) is a worrying presentation. Another presentation is melanoma of the nail bed, often amelanotic. Nail bed melanoma may be difficult to distinguish from squamous cell carcinoma presenting as a fleshy tumour of the nail unit with destruction of the nail. Unfortunately diagnosis of this condition is usually late and prognosis is poor. Management is surgical excision with amputation of the digit. Dermatophyte infection can mimic psoriasis. Nail clippings and scrapings of subungual debris should be sent for microscopy and culture. Onychomycosis is a disease of toenails, often associated with traumatic nail changes. If there are fingernail changes alone, dermatophyte infection is extremely unlikely. Viral warts do not usually cause nail destruction. Bowen’s disease is often mistaken for a viral wart. Biopsy if suspicious. Destruction of an isolated nail should raise the suspicion of malignancy. Longitudinal melanonychia has many causes, the most important of which to rule out is melanoma. Evidence-based practice ■ ■ ■ ■ Treatment of onychomycosis with terbinafine or itraconazole is effective — level A Topical steroids and topical calcipotriol are effective in treatment of nail psoriasis — level A Oral biotin 2.5mg daily helps improve brittle nails — level B Simple topical treatments for warts containing salicylic acid are both effective and safe — level A AD_ 0 4 0 _ _ _ OCT 3 1 _ 0 8 . P DF Pa ge 1 1 0 / 2 3 / 0 8 , 3 : 1 5 PM How to treat – common nail disorders Authors’ case studies GP’s contribution Case 1 DR WENDY MORGAN A 36-YEAR-OLD woman presented with a painful right index fingernail. She had had some trauma to the nail many years before, which seemed to resolve. Over the past eight months she had had a throbbing pain intermittently in the fingertip, which became worse in the cold. On examination the nail was tender, thin and there was an erythematous patch in the middle of the nail bed. The most likely diagnosis was a glomus tumour, with this fairly typical history. MRI could be used to confirm the diagnosis, but it is expensive. In this case the nail was removed, and a typical red mass, fairly well defined, was removed. The nail regrew with some thinning of the plate. The pain was relieved, which pleased the patient. Artarmon, NSW Case study The nail was removed, and a typical red mass, fairly well defined, was removed. Case 2 A 56-year-old man presented with a warty lesion on the lateral side of the right index finger. It had been present for five years and was not responding to cryotherapy or wart paints. He had a past history of genital warts, which occurred about the same time as this lesion appeared, but they had resolved. On examination there was a linear warty growth with some nail destruction. A biopsy confirmed Bowen’s disease (epidermoid carcinoma of the nail). A trial of imiquimod 5% cream was used, but failed. He had Mohs’ surgery and complete excision. Bowen’s disease presenting as linear warty growth with some nail destruction. How to Treat Quiz 2. Brian, 65, comes to see you about his “grotty toenail”. On examination the lateral edge of the nail is thickened, with yellow streaks extending proximally, and there is significant brownish subungual debris. Which TWO statements about onychomycosis are correct? a) Repeated micro-trauma and occlusive footwear are common predisposing factors for onychomycosis b) Superficial white onychomycosis is the most common form of onychomycosis c) Proximal subungual onychomycosis is usually found in immunocompromised patients d) Using fungal microscopy and culture, a falsenegative result occurs in about 10% of cases of onychomycosis 3. Which TWO statements about the treatment of onychomycosis are correct? a) No treatment apart from regular nail clipping is an option What is the periodic acidSchiff test, and is there any role for this in the diagnosis of onychomycosis? The periodic acid-Schiff (PAS) test is a stain done on skin or nail tissue. It is a test that looks microscopically at hyphae in the nail clippings; they turn a red-pink colour and may be positive when the culture is negative. It is a more sensitive test than culture. How important is it to try to confirm onychomycosis in a patient with diabetes? Onychomycosis can be more serious in patients with diabetes and is therefore important to diagnose and treat quite vigorously. It is the associated tinea of the skin and secondary infection that is important rather than just the nail thickening. General question Which are the more-immunestimulating wart paints that are the most successful in treating periungual warts? The one in use by most dermatologists is diphencyclopropenone (DCP), made by compounding pharmacies. A 2% solution is applied to the patient’s arm and when an immune reaction resembling an insect bite develops (at about 10 days) the patient starts to apply a 0.1% solution to the wart each day. This must be done carefully, with occlusion to prevent the solution spreading to other parts of the skin, where it can cause an eczematous rash. The warts usually take 2-3 months to disappear. Correction The Non-alcoholic Fatty Liver Disease HTT (24 October 2008) stated that rosiglitazone is contraindicated in patients with ischaemic heart disease. It should have stated that rosiglitazone is not recommended in patients with known ischaemic heart disease, particularly in those taking nitrates, and is contraindicated in patients with acute coronary syndrome. Australian Doctor apologises for any confusion. INSTRUCTIONS Complete this quiz online and fill in the GP evaluation form to earn 2 CPD or PDP points. We no longer accept quizzes by post or fax. The mark required to obtain points is 80%. Please note that some questions have more than one correct answer. Common nail disorders — 31 October 2008 1. Which THREE statements about nail structure and function are correct? a) The cuticle is important in protecting the nail matrix from the environment b) Rigidity of the nail plate is due to hard keratins c) Water is essential to improve flexibility in the nail plate d) Toenails grow on average at a rate of 0.1mm/day VICTOR, 52, has insulindependent diabetes. His most recent HbA1c was in the suboptimal range, so his insulin dose is being adjusted by the endocrinologist to try to improve his glycaemic control. Despite his suboptimal diabetes control, he does not have any evidence of diabetes-associated peripheral neuropathy. Recently Victor presented with mild cellulitis involving his left great toe. The infection resolved rapidly with oral antibiotics and the toenail was not ingrowing. However, the distal lateral edge of the nail was thickened and discoloured with some subungual debris. The left second toenail and also the right great toenail were similarly affected but to a lesser degree. Suspecting that Victor had onychomycosis, a specimen of the distal left great-toenail was sent for fungal microscopy and culture, but no pathogens were isolated. Questions for the author ONLINE ONLY www.australiandoctor.com.au/cpd/ for immediate feedback b) Topical therapy is of no use for any type of onychomycosis c) Side effects with terbinafine are normally minimal, but agranulocytosis and liver function abnormalities have been reported d) Nail removal is the treatment of choice, as after nail removal the condition will not recur 4. Which TWO statements about nail psoriasis are correct? a) In psoriasis the toenails are more commonly affected than the fingernails b) The ‘oil spot’ is the sign most diagnostic of nail psoriasis c) In psoriasis often all the nails eventually become involved, whereas this is less common for fungal infections d) Psoriatic nails do not spontaneously resolve 5. Which TWO statements about onycholysis are correct? a) Onycholysis may be associated with thyroid disease and psoriasis b) Candida is the most common cause of onycholysis c) Treatment includes advising patients to insert a manicuring instrument under the nail to clean out debris d) Treatment includes drying the nail bed by blow-drying the area with a hair-dryer 6. Jane, 35, is a mother of two children and works part-time as a kitchenhand. She consults you because her fingernails are very brittle. Which THREE statements are correct? a) Clinical features of brittle nails include longitudinal ridging and fissuring of the nails b) Jane should be advised to take a calcium supplement, as calcium deficiency is a common cause of brittle nails c) Treatment would include advising Jane to avoid trauma, detergents and chemicals and to wear rubber gloves d) Oral biotin 2.5mg daily may be helpful for brittle nails 7. Which THREE statements about nail changes in systemic disease are correct? a) Koilonychia is pathognomonic for irondeficiency anaemia b) Beau’s lines may be associated with severe acute illness c) Any acquired clubbing is suspicious and the patient needs to be investigated thoroughly for causes d) If splinter haemorrhages are multiple, this should raise suspicion of systemic causes 8. Which THREE statements about nail tumours are correct? a) MRI of the nail usually detects most glomus tumours b) Incision and drainage is the most effective treatment for a myxoid pseudocyst of the digit c) If destruction of the nail is present, malignancy should be suspected d) Bowen’s disease can involve more than one digit 9. Joe, 60, is incidentally noticed to have a dark brown streak in his left thumbnail. He does not recall any trauma to the nail. Which THREE statements about assessment of longitudinal melanonychia are correct? a) Longitudinal melanonychia may be due to systemic causes, including Addison’s disease b) Melanomas in the nail matrix usually appear as a longitudinal black or brown streak c) Any adult patient with longitudinal melanonychia of a single nail that is not clearly related to a definitive cause should undergo a nail matrix punch biopsy d) Melanomas of the nail occur most commonly on the ring and little fingers and on the fifth toes 10. Joe undergoes a nail matrix punch biopsy, which confirms a diagnosis of melanoma. Which TWO statements about melanoma are correct? a) Acral lentiginous melanoma does not occur in darker-skinned populations b) Melanoma of the nail bed is often amelanotic c) Periungual extension of the pigment onto the proximal or lateral nail fold is a worrying presentation in melanoma of the nail d) The prognosis for acral lentiginous melanoma is generally good CPD QUIZ UPDATE The RACGP now requires that a brief GP evaluation form be completed with every quiz to obtain category 2 CPD or PDP points for the 2008-10 triennium. You can complete this online along with the quiz at www.australiandoctor.com.au. Because this is a requirement, we are no longer able to accept the quiz by post or fax. However, we have included the quiz questions here for those who like to prepare the answers before completing the quiz online. HOW TO TREAT Editor: Dr Wendy Morgan Co-ordinator: Julian McAllan Quiz: Dr Wendy Morgan NEXT WEEK Skin infections and infestations are common problems in children. The next How to Treat puts paediatric skin infections and infestations under the microscope. The author is Dr Gayle Fischer, senior lecturer in dermatology, University of Sydney, and paediatric dermatologist, Royal North Shore Hospital, St Leonards, NSW. 40 | Australian Doctor | 31 October 2008 www.australiandoctor.com.au