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How to treat
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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,
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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.
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31 October 2008 | Australian Doctor |
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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-
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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-
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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
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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-
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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.
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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.
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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-
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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.
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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.
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■
■
■
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.
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| Australian Doctor | 31 October 2008
www.australiandoctor.com.au