Nail Theory & Structure

proximal nail fold (PNF)

the fold of the skin at the base above the nail plate

keratinized nail fold (KPNF)

where the PNF meets the nail plate, skin is keratinized; it is living tissue and cannot be clipped.

nail matrix

creates nail cells that harden & flatten as they move outward to form the nail plate, where new growth starts

eponychium

living tissue under the PNF covering new growth on the nail plate

cuticle

thin layer of nonliving tissue shed by cells in the eponychium; attached to the nail plate, creating a seal between the PNF & nail plate, keeps bacteria out of the matrix

lunula

front portion of nail matrix that creates a half-moon shape at base of nail plate

nail bed

where nail plate rests, the support

bed epithelium

specialized tissue that adheres to nail plate through interlocking grooves

nail plate

extends from matrix to free edge, made of layers of hard, nonliving, keratinized cells with no nerves or blood vessels

lateral nail folds (sidewalls, peronychium)

folds of living tissue/skin on both sides of nail bed & plate; keeps bacteria out of the sides

free edge

part of nail plate that extends beyond finger/toe; protects the tips of the fingers/toes

hyponychium

area underneath free edge that creates a seal to prevent bacteria from nail bed

onychodermal band

glassy, grayish band where the nail plate meets the hyponychium

distal phalax

finger bone

average fingernail growth rate

1/8'' per month

average time to grow new toenail

12-18 months

what do you do before a client?

wash hands + skin & nail analysis

nail is made of what?

keratin

onychosis

any disease, disorder, or condition of the nail

if a disease is present

refer to medical professional

if a disorder is present

perform with caution

if a condition is present

perform with modifications

etiology

the cause of the disease, disorder, or condition

6 signs of infection

pain, swelling, redness, local fever, throbbing & pus

what does a healthy nail look like?

smooth & curved, without hollows or ridges, pink/translucent

4 causes of nail disease

bacteria, fungi, viruses, & illnesses

Onychomycosis (Tinea Unguium)

nail ringworm, fungal infection, contagious

Onychia

inflammation of the PNF or lateral nail folds, not contagious

Onychatrophia

atrophy of the nail, wasting away of the nail plate, not contagious

Onychomadesis

shedding or loss of the nail plate with separation beginning at the matrix, not contagious

Paronychia

inflammation of skin around nail, not contagious

Chloronychia

"greenies", discoloration of nail, contagious

Pyogenic Granuloma

lesion that can form on the hand/foot or on nail bed, not contagious

Koilonychia

spoon nails, nails with concave shape

Horizontal Grooves

horizontal depressions across width of nail

Vertical Grooves

vertical depressions down nail plate

Melanonychia

brown or black color on nail, often vertical stripe

Nail psoriasis

shallow/deep holes in nail (pitting)

Onychogryphosis

increased thickness or curvature of nails

Onychocryptosis

ingrown nail

Onychauxis (hypertrophy)

abnormal outgrowth of nail, thickening of nail plate

Pincer nails

extreme C curve of nail, trumpet nails

Plicatured nails

folded nails, sides of folded nail cut into soft tissue

bruised nails

dark, purplish discoloration under nail

discolored nails

bluish, yellowish or any variety of colors on nail plate

hang nails

splits in PNF or lateral nail folds

Hapalonychia

(eggshell nails) Very thin, soft nails; curve over the free edge

Leukonychia

white spots appearing within nail plate

Onycholysis

loosening or separation of nail plate from nail bed

Onychophagy

bitten nails

Onychorrhexis

splint or brittle nails

Onychoschizia

splitting or peeling of nail plate at free edge, (lamellar dystrophy, delamination)

Pterygium- dorsal top

living skin that becomes attached to nail plate at PNF

Pterygium- inverse bottom

living skin that becomes attached to nail plate at hyponychium

Splinter hemorrhages

red/borwn vertical line undernail plate, resembling wood splinter