Transcript Nail conditions

Mrs Sue Paterson MA VetMB DVD DipECVD
RCVS and European Specialist in Veterinary Dermatology
Rutland House Veterinary Hospital, St Helens, UK
Structure of the canine claw courtesy of Patel, Forsythe
Nail terms
 Onychoclasis – breaking of the claw
 Onychocryptosis – ingrown nail
 Onychodystrophy – abnormal claw formation
 Onychogryphosis – hypertrophy and abnormal curvature of
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the claw
Onychomedesis – sloughing of the claw
Onychomalacia – softening of the claw
Onychomycosis – fungal infection of the claw
Onychorrhexis – longitudinal striations associated with
brittleness and breaking of the claw
Onychoschizia - splitting or lamination of the claw
Paronychia – inflammation or infection of the claw fold
Paronychial
disease –
involves the
nail fold
Nail disease –
involves the
nail
Important to differentiate
between diseases of the nails beds
and those of the nails
Investigation and therapy of each
disease is different
Disease of the nail bed – Dogs
Bacterial paronychia
secondary to allergy,
endocrine disease,
demodex
Malassezia paronychia
secondary to allergy or
endocrine disease
Demodectic paronychia
Leishmaniasis
Neoplastic
Immune mediated
S.L.E.
Pemphigus foliaceus
Bullous pemphigoid
Drug eruption
Disease of the nails – Dogs
Congenital disease – DEB, Ichthyosis
Traumatic injury –RTA
Onychomycosis
Vasculitis
Dermatomyositis
Leishmaniasis
Idiopathic lupoid onychodystropy
Disease of the nail bed – Cats
Bacterial paronychia
secondary to allergy or
FIV, FeLV
Malassezia paronychia
secondary to allergy or
endocrine disease
Viral paronychia
calici, herpes, pox
Demodectic paronychia
S.L.E.
Pemphigus foliaceus
Bullous pemphigoid
Drug eruption
Neoplastic
met bronchial
carcinoma
Disease of the nails – Cats
Traumatic – RTA
Onychomycosis
Vasculitis
Idiopathic onychodystrophy
Investigation of nail disease
History
Physical examination
Dermatological examination
Examination of nail
 Examination of the nail / nail bed is
important to establish which structure is
affected
 In some case paronychial disease and
nail disease is present concurrently
Investigation of nail disease
Diagnostic tests
 Samples from nail beds – skin scrapes,
hair plucks, cytology
 Nail trimmings for dermatophytes
culture
 Removal of nail for histopathology ?
BIOPSY TECHNIQUES
Symmetrical lupoid
onychodystrophy
Approach to a nail case
 History – breed, age, life style
 Physical examination – signs of systemic ill
health
 Dermatological examination – evidence of
involvement of other areas, e.g. face, other
mc junctions
Symmetrical lupoid onychodystrophy
Aetiology
Uncommon to rare immune mediated claw loss
Usually young adult - middle aged dogs esp. GSD
Initial signs are of loss of 1 – 2 nails but disease is
progressive and over weeks to months all claws will
slough
Replacement claws are usually misshapen, soft, brittle,
friable and will slough again without therapy
Feet usually painful and dog may be lame
This is a diagnosis of exclusion
Initial diagnostic tests
 Cytology of any exudate
 Bacterial culture of exudate when
appropriate
 Fungal culture of claw clippings
 Bloods if systemic disease is suspected
 Biopsy of skin if generalised disease is a
potential differential diagnosis
 Histopathology of P3
Initial diagnostic tests
 Diagnostic
histopathology of P3
 Hydropic degeneration,
apoptosis of individual
keratinocytes in basal
cell layer, pigentary
incontinence, lichenoid
interface dermatitis
Symmetrical lupoid onychodystrophy
Differential diagnosis
Dermatophytosis
Trauma
Autoimmune disease e.g. pemphigus
foliaceus
Immune mediated disease – vasculitis,
dermatomyositis
Further investigation
 A diagnosis of onychodystrophy is made by
exclusion of other causes  Removal of all nails by traction should be
undertaken
 Dog anaesthetised with full analgesia.
 The feet are clipped and prepared surgically
 Each nail is grasped in turn with a pair of artery
forceps and is twisted and pulled to remove it
 Cultures taken from nail bed and nail submitted
for fungal culture
Post operatively
 Dog feet are dressed & hospitalised for 48 hrs
 Antibiotics given usually Cephalexin 25mg/kg
bid plus analgesia Tramadol 2 – 5 mg / kg bid
 After 24 hours dressings removed, feet gently
cleaned – under GA if necessary. No further
dressing are applied
 Dog sent home initially with more antibiotics,
pain relief and a large buster collar
10 day recheck – ongoing tx
At 10 days analgesia and
antibiotics can be discontinued
Ongoing treatment
Immune modulators
Nutritional supplements
10 day recheck – ongoing tx
Immune modulators
 Tetracycline or
Doxycycline and
Niacinamide
 Glucocorticoids
 Azathioprine
 Ciclosporine
 Pentoxyphylline
10 day recheck – ongoing tx
Nutritional
supplements
 Omega 6 and /or
omega 3 EFAs
 Biotin
Tetracycline/doxycycline + niacinamide
 Dogs < 15kg Tetracycline 250mg with Niacinamide
250mg tid
 Dogs > 15kg Tetracycline 500mg with Niacinamide
500mg tid
 Alternative to tetracycline - Doxycycline 10mg/kg sid
 Precise mechanism unknown.
 Tetracycline and Doxycycline both have antiinflammatory and immune modulating activity
 Niacinamide shown to have range of antiinflammatory effects
 Combination useful in DLE and pemphigus as well as
lupoid onycodystrophy
Glucocorticoids
 Have been shown to be useful in many case,
only start once any bacterial or fungal
infection has been resolved
 Dose rate is very variable
 Low dose therapy
 Prednisolone 0.5mg/kg sid/eod po
 High dose therapy
 Prednisolone 2.0mg/kg sid/eod po
 Gastric protectants useful if using the higher
dose rate
Azathioprine / Cyclosporine
Both drugs can be used with or to replace
steroids
Azathioprine 2mg/kg po sid up to 3 months
until remission is seen then eod.
 Dogs must be monitored for changes in liver
function and bone marrow
Cyclosporine 5m/kg po sid up to 3 months until
remission and then taper to eod or biw
 Monitoring not necessary in a healthy dog,
but cost may be prohibitive
Omega 6 and /or
omega 3 EFAs
 Essential fatty acids
increasing the
suppleness of thin,
brittle nails.
 Important in dogs
when exercising
and when nails are
cut
 Dose 300mg EPA /
10kg daily or
 200mg GLA / 10kg
daily
Pentoxiphylline 10-24
mg/kg bid/tid
 Immunodulatory drug
in man useful for
treatment of
peripheral vascular
disease and vasculitis
 Been shown to be
useful for similar
conditions in dogs
Biotin - Human studies
 Biotin supplementation increases
nail thickness by 25 percent in 63%
of a group of patients with brittle
nails. (Floersheim GL 1989).
 Patients taking biotin daily for 3-6
mths had reduced brittleness &
splitting (Hochman LG et al 1993).
 Increased nail thickness as
identified by scanning EM was
recorded after biotin
supplementation. (Colombo VE et
al 1990).
Typical combination therapy
 Essential fatty acids GLA 200mg/10kg sid po or
300mg/10kg sid po
 Biotin 2.5- 3mg daily/ dog
 Prednisolone 0.5mg/kg eod po
 Pentoxyphylline 10mg/kg tid po
 Continue therapy for 6 weeks then reassess
 If dog making progress consider with drawing
Pentoxyphylline, continue with other drugs long
term
Failure to respond to therapy
 Switch to a different immune modulator
 Azathioprine
 Ciclosporine
 Tetracycline / doxycycline with niacinamide
 Surgical intervention to amputate all of the
claws.