Differential Diagnosis > Distribution > Acral > Nails

Nails

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hmtoggle_plus1Subungual Hyperkeratosis ddx:
=abnormal production of cornified cells by the nail bed
fungal
psoriasis
pachyonychia congenita
PRP
idiopathic (occurs with old age)

 

hmtoggle_plus1onycholysis ddx:
fungus
drug
trauma
psoriasis

 

hmtoggle_plus1Blue lunula ddx:
Wilsons disease (rare)
argyria
drugs: (phenophthalein, busulfan, anti-malarials)

 

Cutaneous disease:

psoriasis pitting; oil drop; subungual hyperkeratosis; onycholysis; splinter hemorrhages
lichen planus
onychomycosis

 

Nail Disorders:

Twenty nail dystrophy (“of childhood”);
Yellow Nail syndrome
Laugier-Hunziker syndrome

 

hmtoggle_plus1Nail Findings in Systemic Disease:
Systemic Sclerosis inverse pteryigium and nail beaking

Leukonychia:

Terrys nails
Half and Half nails
Muehrkes paired white bands
Mees lines

Nail Fold Capillary Microscopy:

scleroderma
dermatomyositis
SLE

 

Genodermatoses:

Ectodermal dysplasia hydrotic - anonychia and micronychia; anhidrotic - normal nails
Nail-Patella syndrome in every case, the thumb nails are always involved (hypoplastic nails)
Pachyonychia congenita pincer nails
Tuberous Sclerosis (Koenen’s tumor i.e. periungual fibroma)
Wilsons disease:

 

Hyperpigmentation:

Hutchinson’s sign
AZT nails drug stimulates melanogenesis (similar mechanism to chemo), therefore it is NOT the drug that deposits

 

Glossary:

pachyonychia thickening of the entire nail plate;  may be found idiopathically in older persons
trachyonychia refers to rough nails with a sandpaper texture and appearance, as found in twenty nail dystrophy

 

 

 

Proximal portion of the matrix forms the superior aspect of the nail plate, and the distal matrix contributes to the inferior portion of the plate…

 

Pits:

evidence of pinpoint damage to the matrix
represent loci where tiny clusters of parakeratotic cells have been shed from the surface of the nail plate

 

White spots (leukonychia):

result from damage to the distal matrix (vs. pits)
represent parakeratotic cells in the deeper portion of the nail plate