Onychomycosis / Tinea Unguium
Onychomycosis (tinea unguium), or fungal nail infection, is the most common chronic infection of the nail unit and accounts for more than half of all nail abnormalities seen in clinic. It is caused by three main groups of organisms: dermatophytes, yeasts and non-dermatophyte molds (NDMs).
The nail plate is made of layers of hard keratin held tightly together by disulfide bonds and lipid membranes. To break into this structure, fungi rely on a powerful set of protein-digesting enzymes.
- Enzymatic keratinolysis: Fungi, especially T. rubrum, secrete keratinases, proteinases and lipases. These enzymes break hard keratin down into short peptides and amino acids, which both feed the fungus and undermine the mechanical integrity of the nail plate.
- Subungual hyperkeratosis: As a defensive response to invading hyphae, the nail bed overproduces epidermal cells. These cells keratinize abnormally (parakeratosis), forming a crumbly, chalky layer under the nail packed with fungal hyphae and spores (arthrospores).
- Fungal biofilm and nail separation (onycholysis): As hyphae spread along the grooves of the nail bed, they produce a tightly adherent fungal biofilm. This breaks the natural attachment between the nail plate and nail bed, leaving a gap filled with dead keratin debris.
Nail fungus is more than a cosmetic problem. It is a persistent fungal reservoir that can spread to other nails and to family members, and in people with diabetes or poor peripheral circulation it can open the door to staphylococcal or streptococcal cellulitis. Over-the-counter creams rarely work, because the active ingredients cannot get through a thickened nail plate. At Haute-Derma, our protocol combines medical debridement to clear the keratin buildup, 1064 nm Nd:YAG laser to destroy fungal spores with heat, and targeted delivery of antifungal agents.
Clinical Types and Diagnostic Onychoscopy Signs
Typical Clinical Patterns
- DLSO (distal lateral subungual onychomycosis): The most common pattern (> 80%). The fungus enters from the free edge or side of the nail, turning it yellow or opaque white, with subungual hyperkeratosis and separation that gradually advances toward the base.
- WSO (white superficial onychomycosis): The fungus (often T. mentagrophytes) attacks the top surface of the nail directly, producing irregular chalky white patches; the nail becomes brittle and flakes off when lightly scratched.
- PSO (proximal subungual onychomycosis): The fungus enters from the proximal nail fold straight into the matrix, creating an opaque white area near the base of the nail. This pattern is a warning sign of significant immunosuppression (such as HIV infection) or long-term corticosteroid use.
- TDO (total dystrophic onychomycosis): The end stage. The entire nail plate is destroyed, leaving only a rough, thickened, bulbous remnant at the base.
- Candida onychomycosis: Often accompanied by chronic paronychia: the proximal nail fold is red and swollen, the cuticle is lost, a little thin pus may seep out, and the nail turns gray-brown or green-black along both sides.
Characteristic Onychoscopy (Nail Dermoscopy) Signs
- Jagged proximal border with spikes: The proximal edge of the opaque area has sharp spikes pointing toward the nail base, a highly sensitive sign that helps distinguish infection from trauma.
- Aurora borealis pattern: Longitudinal streaks running along the nail in a mix of colors (yellow, gray, orange, brown).
- Subungual ruin appearance: The keratin mass under the nail looks chalky, crumbling and irregularly broken.
How Nail Fungus Differs From Look-Alike Conditions
| Onychomycosis | Nail Psoriasis | Traumatic Nail Dystrophy |
|---|---|---|
| Fungal infection (dermatophytes / Candida) | Chronic autoimmune inflammatory disease | Repeated mechanical trauma / tight shoes |
| Yellow/brown opacity, subungual hyperkeratosis, crumbling | Pitting, oil-drop spots, pink band | Limited onycholysis, purple/black subungual hematoma |
| Jagged spiked border, aurora pattern | Dilated looped vessels in the nail fold, orange-red oil drops | Straight, smooth lesion border, pinpoint hemorrhages |
| Usually a few nails, asymmetric | Often many fingernails and toenails, symmetric | Usually weight-bearing toes (big toe, little toe) |
| KOH (+) / fungal culture (+) | KOH negative | KOH negative |
Our Medical Approach and Treatment at Haute-Derma
At Haute-Derma, we treat nail fungus with a combined photothermal and targeted-delivery strategy that protects the nail matrix (the Haute-Derma Matrix-Sparing Onychomycosis Protocol), designed to clear fungal spores hidden deep under the nail plate without harming the matrix.
Step 1: Same-Day Microbiological Testing
- Direct KOH (10–20%) microscopy: Keratin debris from deep under the nail is examined under the microscope to confirm septate hyphae or yeast cells within about 20 minutes.
- Onychoscopy of the matrix area: We map the edges of the infection and check whether the proximal matrix is involved.
Step 2: Medical Subungual Debridement
- Using a sterile medical burr, the dermatologist gently thins the opaque, crumbling nail and removes the dead keratin mass and fungal biofilm beneath it.
- Purpose: To remove the fungal "reservoir" and expose the nail bed, so that laser energy and antifungal drugs reach their target more effectively.
Step 3: Long-Pulsed 1064 nm Nd:YAG Laser to Destroy Fungal Spores
- Selective photothermal therapy: Long-pulsed 1064 nm laser energy passes through the nail plate and nail bed, raising the temperature locally within the infected area and killing fungal spores.
- Advantages: The heat denatures proteins and damages both actively growing hyphae and heat-resistant, thick-walled spores, while keeping pain and the risk of burns to surrounding healthy tissue low.
Step 4: Targeted Antifungal Delivery (TDD) and Matrix Recovery
- High-strength antifungal solutions (such as amorolfine 5% or ciclopirox olamine) are delivered directly into the freshly cleaned nail bed.
- A peptide serum that supports the nail matrix is applied to boost new keratin production, helping a healthy, pink, smooth nail grow out faster.
