ONYCHOLOGY Flashcards
how is the normal nail plate?
usually clear and transparent allowing visualization of the underlying pink nail bed
normal nail matrix or root starts in utero at about how many weeks?
9-10 weeks
the entire nail unit is derived from?
ectoderm
epidermis
what is this disease?
aka koenen tumor (benign) inherited neurocutaneous multiple benign hamartomas variable expression a clinical diagnosis
periungual fibromas of tuberous sclerosis complex
– Abnormal thickening but not distorted in shape – Greater than 0.2 mm in thickness
Onychauxsis
– Greater thickening in
both transverse and
longitudinal dimensions
Onychogryphosis
– Normal but elongated
Hypertrophic nails
– traumatic or surgical and partial or complete
Matrix destruction
– intermittent atrophy produces Beau’s lines
– continued produces onychomadeisis – shedding
• Found in Hand Foot and Mouth disease
Atrophy of matrix
– gradual microtraumatic‐onychochauxsis
• uniform flat thickening 1‐3 mm thick
– acute traumatic onychogryphosis
• distorted in all planes 3‐15 mm thick
Hypertrophy of matrix
– due to allergic contact dermatitis to acrylic
Onycholysis
what are the primary tumors?
metastatic tumors?
squamous cell carcinoma
basal cell carcinoma
kaposi sarcoma
melanoma
breast cancer produces phalangeal osteolytic focus
what is this malignant tumor?
Commonest malignant tumor of the nail unit
Squamous cell carcinoma SCC
what is this malignant tumor?
• Although BCC are the most common malignant skin tumor, they are very rare as a
subungual tumor
• Pedal nail units usually protected from solar
exposure
Basal cell carcinoma BCC
what is this carcinoma?
Resembles benign diseases
Look for nail plate variation and nodularity
Melanonychia, erythronychia,
irregular vascularity, splinter
hemorrhages
Subungual SCC
subungual metastases largely occur from?
lung
first sign of previously unsuspected primary malignancy in 44% of the patients with sublingual metastases?
– Painful erythematous swelling of the distal digit
– Red to violaceous nodule distorting nail soft tissue
– Often mistaken as an acute infection.
metastatic sarcoma presents
with white lines on all of her
fingernails
– Not toenails
Muehrcke’ Lines
Typically non‐painful spreading
discoloration of nail bed
2/3 presents as longitudinal
melanonychia
Diagnostic delay ‐ poor prognosis
Equal sex predilection
Subungual Melanoma
characteristics of Subungual Melanoma?
age of patient band of brown breadth greater than 3 mm border irregular or blurred change in the band digit involved decreasing frequency extension of pigment fx of melanoma
Dermoscopy Signs of
Subungual Melanoma?
brown background
irregular
micro hutchinson sign
biopsy is gold standard
1/3 of subungual melanomas are amelanotic
Poor prognosis
Older patients
Linear irregular vessels
Milky red areas
what is this?
Amelanotic Melanoma
Subungaul hematoma should growth out how many mm per month?
1mm per month
Clinical observation of subungual pigment appears to stain the overlying cuticle because of nail plate transparency but actually does not.
Absence does not necessarily
imply benignity
what is this sign?
Pseudo‐Hutchinson’s Sign
‘The Greenies’ ‐ nail technician’s name for chronic
subungual Pseudomonas infection
Prolonged immersion in fresh water
Green is pyocyanin pigmented subungual debris
Topical fluoroquinolones
Antiseptic soaks for 2 weeks
Oral ciprofloxacin for four weeks has been found to be effective
Treatment failure ‐ cultures and sensitivity testing, nail removal
Green Nail Syndrome
