HARP
Hyperkeratosis – thickening of cornified layer
Acanthosis – epidermal thickening (3-5 times normal)
Rete ridge elongation (arrowheads)
Parakeratosis – retained nuclei in stratum corneum
STOP
Subungal Hyperkeratosis (proliferation under nail bed)
Thickening
Onycholysis (separation from nail bed)
Pitting, ridging
Also Remember
Absence of granular layer and infiltration with neutrophils and activated lymphocytes (from dermis to epidermis)
Nail Changes (as much as 50% of the patients)
