Nail Care and Manicuring
Anatomy and growth
The nail plate rests on the nail bed and is produced by the matrix; the lunula is the visible portion of the matrix. The eponychium is the living fold of skin at the base, while the cuticle is the dead tissue clinging to the plate - questions frequently confuse the two. Other landmarks: hyponychium, free edge, lateral folds, nail grooves, and mantle. Fingernails grow about 1/8 inch per month, faster in summer and on the dominant hand, and slower on toenails.
Disorders versus diseases
Onychosis describes a deformed nail; onychocryptosis is an ingrown nail; onychomycosis is a fungal infection; paronychia is inflammation of the tissue around the nail; onychorrhexis is splitting; onychauxis is thickening; pterygium is forward growth of the eponychium; Beau's lines are horizontal depressions; leukonychia is white spotting; melanonychia is dark pigmentation. Fungal and bacterial infections, pus, and severe inflammation are referred to a physician - a cosmetologist never treats them.
Products and safety
Acrylic is a monomer/polymer system; gel is cured by UV/LED; wraps use fabric and resin. Methyl methacrylate (MMA) is banned for nail use in Michigan and most states - use ethyl methacrylate (EMA). Disinfect reusable implements in an EPA-registered hospital-grade product at full contact time; porous files and buffers are single-use. Foot spas and pedicure basins require dedicated cleaning protocols because biofilm hides in jets and screens.
Worked example
A client shows a green-black discoloration on one nail. That suggests Pseudomonas ("greenies") - a bacterial infection. Do not file over it, do not apply product, and refer. Traps include calling the cuticle living tissue and assuming a stained nail can be cosmetically covered.