Nails Flashcards
What is protects the nail matrix
proximal nail fold
cuticle
eponychium
what is the nail matrix
germinative cells that produce the nail plate
What produces the dorsal nail plate
proximal matrix
What produces the ventral nail plate
distal matrix (lunula)
What are diseases due to abnormal matrix function?
Koilonychia (spoon nails); true leukonychia; trachyonychia; pitting; Beau’s lines
What are often traumatic transverse depression of the nail plate?
Beau’s lines
What is the secondary cause of Beau’s lines?
disruption of nail plate formation by nail matrix
How would Beau’s lines indicate systemic cause?
presence at same level in all nails
What are punctuate depression of the nail plate surface?
pitting (migrates distally with growth)
pathogenesis of pitting
due to foci of abnormal keratinization in proximal nail matrix
patients typically presenting w/ pitting
psoriasis; alopecia; areata; eczema
What are nails with a rough, ridged surface?
trachyonychia
patients with trachyonychia are damaged via what? what diseases are associated?
proximal nail matrix damage => alopecia areata; lichen planus; psoriasis; eczema
What is True leukonychia? what causes it?
white opaque discoloration => traumatic damage of distal matrix
What are Mees’ lines?
true leukonychia w/ transverse white bands that are associated with arsenic and thallium toxicity
What differentiates true leukonychia from apparent leukonychia?
press on the nail => true remains unchanged with pressure
What are thin, flat, spoon shaped nails?
kiolonychia
What is the pathogenesis of koilonychia
hereditary or acquired causes such as iron deficiency anemia
What are nail bed disorders?
onycholysis; apparent leukonychia; splinter hemorrhage
What is a splinter hemorrhage?
sliver of extravasated blood visible beneath nail plate
How are Splinter hemorrhages caused?
damage to longitudinally oriented nail bed capillaries commonly from trauma
Splinter hemorrhages are common in what systemic disease?
systemic association is bacterial endocarditis
What is apparent leukonychia?
white discoloration that fades with pressure while nail plate transparency maintained
What is an often cuase of apparent leukonychia?
drugs (CTX) or systemic diseases
What is a distal nail plate detachment from the nail bed?
onycholysis (looks yellow-white)
What is a common cause of onycholysis
psoriasis or onychomycosis
What are nail signs due to deposition of pigment?
longitudinal melanonychia; green nail syndrome
What causes longitudinal melanonychia?
melanocyte activation, non-melanocytic tumors, melanocyte hyperplasia, nevi, melanoma
If a single band is on a nail, what is the likely cause?
melanoma
If multiple bands are on the nail, what is the likely cause?
drugs or systemic disease
What is the epidemiology of longitudinal melanoychia?
90% in african americans
What is Hutchinson’s sign?
extension of pigment on to the nail folds and presence raises concern for melanoma
Green nail syndrome is typically associated with what?
discolored bc of pyocyanin due to pseudomonas aeruginosa
What are predisposing factors for green nail syndrome?
water exposure; detergents; soaps
What are the diagnostic nail signs of psoriasis?
irregular pitting; salmon patches; onycholysis with erythematous border
What are the diagnostic nail signs of lichen planus?
multiple nails suffering from thinning and fissuring caused by dorsal pterygium
What is dorsal pterygium?
scarring of proximal nail fold over the nail plate
What are nail diagnostic signs of alopecia areata?
geometric pitting most commonly seen in children with associated trachyonychia
What are signs of eczema associated with nails?
irregular pitting and Beau’s lines; subungual hyperkeratosis; chronic paronychia
What is Lovibond’s angle?
angle between proximal nail fold and nail plate
If Lovibonds angle is greater than 180*, what is the Dx?
clubbing
Clubbing is associated with what diseases
CP disease; sarcoidosis; cirrhosis; GI disease; toxin exposures; trauma
Muehrckes lines are seen as what?
apparent leukonychia with transverse white bands that disappear with pressure
What are Muehrcke’s line associated with?
hypoalbuminism
if a patient has recurrent episodes of acute paronychia, what may be the cause?
HSV infection
If a patient presents with nails being white proximally and red distally, what disease is associated?
chronic renal disease showing Lindsay’s nails of apparent leukonychia
A patient with cirrhosis will have what type of nails?
terry’s nails: white proximally with 1mm of brown-red distally
If a patient has an autoimmune connective tissue disorder, how will the nails present? what are these typical diseases?
nail fold capillary abnormalities; cuticular hemorrhages => dermatomyositis and scleroderma
What is acute paronychia?
swollen, red and painful compression of nail fold producing purulent drainage
what is acute paronychia commonly due to?
bacteria (S. aureus or S. pyogenes)
Chronic paronychia is commonly due to what
candida infection
How will HPV present on the skin?
warts; periungual keratotic papules; hyperkeratosis of cuticle; onycholysis of nail bed
If recalcitrant lesions occur associated with HPV, what could be associated?
squamous cell carcinoma
What is fungal infection of the nail?
onychomycosis
Trichophyton rubrum causes what type of infection?
tinea unguium that is secondary to dermatophyte infection
What are the 4 patterns of onychomycosis?
distal subungual; white superficial; proximal subungual; candidal onychomycosis
If onychomycosis presents as proximal subungual (PSO), what association does it have?
immunosuppresion/HIV infection
What is onychoschizia? cause?
distal superficial splitting of nail plate from dehydration and frequent hand washing
What is chronic paronychia? cause?
proximal nail fold inflammation w/ absence of cuticle => chronic irritation of Candida infection
What is onychotillomania?
no cuticle and proximal nail fold inflammation with nail plate surface abnormalities associated with melanonychia
What is the cause of subungual hematoma?
acute trauma leading to blood under nail plate and pigment moves distally w/ growth
What is onychogryphosis?
Ram’s horn nails that is favored by chronic trauma and elderly patients
What are pincer nails? cause?
over curvature of distal nail plate => hereditary or acquired (bad fitting shoes)
Onychocryptosis cause?
ingrown nails from improper nail cutting and hyperhidrosis with growth of granulation tissue
What is a pyogenic granuloma?
benign bleeding angiomatous nodule that is periungual or subungual => cause is trauma
What are Periungual fibromas?
papules from proximal nail fold that may compress nail matrix leaving a longitudinal groove in nail plate
What is periungual fibromas a possible sign of?
tuberous sclerosis => Koenen’s tumors
What are myxoid cysts?
proximal nail fold swelling from nail plate depression and grooves => connected to DIP join and drain fluid
What are subungual exostosis?
benign bony proliferation causes subungual, hard nodule usually from trauma
***What is the most frequent malignant tumor of the nail apparatus?
squamous cell carcinoma***
What relationship does SCC and HPV have?
causative role of HPV suggests tumor development
What is the clinical presentation of SCC?
verrucous lesion; ulcerated nodule; onycholysis; nail plate destruction
Melanoma most frequent site of nail?
thumb leading to nail plate destruction => Hutchinson’s sign
