7.3 Nail Diseases and Disorders
Key Takeaways
- Nail disorders such as onychauxis, onycholysis, onychorrhexis, and Beau's lines are structural and non-contagious, so they are generally serviceable with adjusted technique
- Onychomycosis (tinea unguium), paronychia, and onychia involve a fungal or bacterial pathogen and require refusing the service and referring the client to a physician
- Tinea pedis on the skin of the foot is a pedicure-relevant contagious fungal disease that requires refusing service on the affected foot
- Sealing polish or an enhancement over any active infection, even on a nail disorder that is normally serviceable, is never acceptable because it traps pathogens against living tissue
- A simple three-question habit, structure only, pathogen present, or active inflammation and discharge, resolves nearly every nail analysis question on the exam
Nail Diseases and Disorders
Quick Answer: Nail disorders are structural, non-contagious changes to the nail plate, bed, or surrounding tissue, and most are serviceable with modified technique. Nail diseases involve a fungal or bacterial pathogen and require refusing the enhancement or polish service and referring the client for treatment.
Common Nail Disorders (Non-Contagious)
| Disorder | Description | Service Decision |
|---|---|---|
| Onychauxis | Abnormal thickening of the nail plate | Proceed; thin carefully with an appropriate implement |
| Onychatrophia | Atrophy or wasting of the nail; it shrinks and may separate | Proceed gently; avoid enhancement over a very thin, weak nail |
| Onychocryptosis (ingrown nail) | Nail grows into the surrounding skin | Proceed if mild with no infection; refer if red, swollen, or draining |
| Onychophosis | Callus-like growth of skin around or under the nail | Proceed; carefully reduce the buildup |
| Onychoptosis | Periodic shedding of one or more nails | Proceed with gentle care; avoid trauma to the loosening nail |
| Onycholysis | Nail plate separating from the nail bed, usually at the free edge | Proceed with caution; never seal an enhancement over the separated area |
| Onychorrhexis | Abnormal brittleness with lengthwise splitting or ridges | Proceed; recommend strengthening treatments and avoid harsh filing |
| Hangnail (agnail) | Split or torn cuticle at the nail edge | Proceed; carefully trim, avoiding further tearing |
| Nail pterygium | Cuticle growth extends abnormally over the nail plate | Proceed; gently and gradually push back, never cut aggressively |
| Beau's lines | Visible horizontal depressions or ridges across the nail plate | Proceed; usually reflects a past illness or trauma, not a current risk |
| Leukonychia | White spots or patches on the nail plate | Proceed; purely cosmetic, caused by minor nail bed trauma |
Contagious or Infectious Nail Diseases: Refuse and Refer
| Disease | Cause | Key Signs | Action |
|---|---|---|---|
| Onychomycosis (tinea unguium) | Fungal | Thickened, discolored (yellow/white), crumbly nail | Refuse polish or enhancement service; refer to a physician |
| Paronychia | Bacterial infection of the tissue around the nail | Red, swollen, tender, possibly pus-filled | Refuse service; refer to a physician |
| Onychia | Infection or inflammation of the nail matrix | Inflammation, sometimes pus, at the nail base | Refuse service; refer to a physician |
| Tinea pedis (athlete's foot, on the skin of the foot) | Fungal | Itchy, scaling, sometimes cracked skin between the toes | Refuse pedicure on the affected foot; refer to a physician |
Why Enhancement Over Infection Is Never Acceptable
A recurring exam theme is that sealing a product, whether polish, gel, or an enhancement, over any active infection traps moisture and pathogens against living tissue, which can worsen the condition and create legal liability for the salon. Even a nail disorder that is normally fine to service, such as onycholysis, becomes a refusal if the exposed nail bed shows redness, discoloration, or discharge, because that appearance signals a secondary infection has developed in the gap.
Building Your Nail Analysis Habit
During every consultation, examine the nail plate, the nail bed color, the surrounding tissue, and the cuticle before choosing a service. Ask three questions. Is this a shape or structure issue only, meaning it is a disorder you can proceed with? Is there a pathogen present, meaning it is a fungal or bacterial disease requiring refusal and referral? Is there active inflammation, pus, or discharge regardless of the underlying cause, meaning you refuse until it resolves? This same three-question habit is what the PSI exam is testing when it presents a nail description and asks for the correct next step.
Telling Fungal and Bacterial Nail Conditions Apart
The exam often expects you to distinguish a fungal disease from a bacterial one by the details given, not just the name. Fungal infections such as onychomycosis tend to develop slowly, thicken and discolor the entire nail plate toward yellow, white, or brown, and often start at the free edge and spread toward the cuticle. Bacterial infections such as paronychia and onychia tend to appear faster, concentrate in the soft tissue around the nail rather than the plate itself, and produce redness, swelling, tenderness, and sometimes visible pus. Either way, the required action is identical: refuse the polish or enhancement service and refer the client to a physician, because a cosmetologist is never authorized to treat an infection, only to recognize one and redirect the client to appropriate care.
Connecting Nail Findings to the Whole Consultation
Nail findings rarely exist in isolation. A client with diabetes, poor circulation, or a weakened immune system is more likely to develop a nail infection from a minor injury, and a nail disorder on one hand or foot should prompt you to check the others for similar findings. Pedicure clients deserve the same scrutiny as manicure clients, since closed shoes and damp conditions make the feet especially prone to fungal disease; always inspect between the toes and around the nail folds before beginning any pedicure. Recording what you observe on the consultation card, along with your proceed, modify, or refer decision, protects both the client and your license if a condition worsens later.
Which nail disorder is described as the nail plate separating from the nail bed at the free edge, without any pathogen present?
A client's nail is thickened, yellowed, and crumbly at the free edge. What is the most likely diagnosis and correct action?
What is the appropriate action when a client has red, swollen, tender tissue with pus around the nail fold?