Nail Structure, Disorders, and Diseases
This domain tests nail anatomy and your ability to recognize conditions that are safe to service versus conditions that require referral. The exam expects you to use correct terms and to stay inside the nail technician's scope.
Anatomy you must know
- The nail plate is made of keratin and sits on the nail bed.
- The matrix produces the nail plate; damage to it can cause permanent ridges or distortion.
- The cuticle is dead tissue that seals the nail base. The eponychium is the living fold of skin at the base; do not cut living tissue.
- The hyponychium seals the area under the free edge. The lunula is the visible portion of the matrix.
- Fingernails grow about 3 mm per month; toenails grow more slowly. Growth is faster in summer and on the dominant hand.
Disorders versus diseases
A disorder is not necessarily infectious; a disease may be infectious or systemic. Onychomycosis is a fungal infection, paronychia is inflammation or infection around the nail fold, onycholysis is separation of the plate from the bed, koilonychia is spooning, Beau's lines are transverse depressions, leukonychia is white spotting, and melanonychia is dark pigmentation. Refer contagious, painful, swollen, or unexplained conditions.
Worked example
A client has green-black discoloration under an acrylic enhancement. Reasoning: this suggests a bacterial or fungal problem, often Pseudomonas, and the area may be moist and lifting. The technician should not cover it with fresh product or treat it with bleach. Remove the enhancement, advise the client to seek medical evaluation, clean and disinfect implements, and document the referral.
Traps that cost marks
- Confusing the cuticle with the eponychium can lead to cutting live tissue.
- Do not diagnose or promise a cure; refer.
- A dark band under the nail is not automatically a bruise and should be evaluated.
- Do not service an active infection or an open, inflamed area.