Nail Anatomy and Disorders
What the exam tests
This domain tests the structures that produce and support the nail plate and the technician's duty to recognize abnormalities without diagnosing them. The matrix creates the nail plate; the lunula is the visible portion of the matrix; the nail bed supports the plate; the hyponychium seals the free edge; the eponychium is the living proximal fold; the cuticle is nonliving tissue adhering to the plate; lateral folds frame the sides. Fingernails grow about 3 to 3.5 mm per month, toenails about 1.5 mm per month, and growth slows with age and poor circulation.
Core rules
- The nail plate is keratin and has no nerves or blood vessels; the bed and folds are living tissue and bleed.
- Do not cut living tissue. Push back only softened, nonliving cuticle and nip only a hangnail with sterile nippers.
- Recognize and refer: onychomycosis, paronychia, onycholysis, pincer or ingrown nails, new or changing dark streaks, sudden ridging, and green-black discoloration.
- Document what you see and what you advised, using neutral language.
Worked example
A client has a dark brown streak under one nail that has widened over three months. Reasoning: a new or changing longitudinal streak can be benign pigment or melanoma and is outside nail-technician scope. Do not file over it, do not cover it with opaque product, and refer to a physician. Document the referral and offer services on other nails only if the client agrees.
Traps
Calling yourself a diagnostician; treating fungus with salon products; cutting cuticles to make nails look longer; and assuming all discoloration is stain. Also watch for over-filing the nail plate, which thins it and causes sensitivity.