Onycholysis: Symptoms, Types, Causes and Treatment

Onycholysis, the separation of the nail plate from the underlying nail bed, is a surprisingly common and often distressing nail disorder. While it may appear like a simple cosmetic issue, onycholysis can be a clue to deeper systemic illnesses, infections, or environmental exposures. In this comprehensive guide, we'll break down the symptoms, types, causes, and effective treatments for onycholysis—empowering you with knowledge to identify and manage this nail concern.

Symptoms of Onycholysis

Onycholysis can sneak up on you. It may start subtly but can quickly become noticeable and, at times, alarming. Understanding its symptoms is the first step in recognizing and addressing this condition.

Symptom	Description	Commonality	Source
Nail separation	Detachment of nail plate from nail bed	Most frequent	1,4,6
Discoloration	White, yellow, green, purple, or gray hues	Varies by cause	2,9
Concave border	Distal edge often concave or half-moon	Common in subtype	1,3,9
Dirt trapping	Accumulation of dirt under lifted nail	Frequent	1,9

Table 1: Key Symptoms

Recognizing the Signs

Onycholysis typically presents as a painless separation of the nail plate from the nail bed, most often starting at the distal (far) edge. The detached area appears white due to the air underneath, but depending on the underlying cause, the nail can also take on yellow, green, purple, gray, or even black hues. This discoloration often results from secondary colonization by bacteria, fungi, or simply dirt trapped in the new space under the nail 1,2,9.

Patterns and Progression

• Shape: The edge of separation is frequently concave or half-moon shaped, especially in cases linked to hyperthyroidism or phototoxic reactions 1,3,9.
• Pain: Notably, onycholysis is rarely painful at onset, though pain or tenderness may develop if infection sets in or if the nail is traumatized further 2.
• Dirt Accumulation: The hyponychium (the skin under the free edge of the nail) tends to trap dirt and debris, contributing to a dirty or dark appearance 1,9.
• Multiple Nails: While it can begin in a single nail, onycholysis may spread to others, especially if the underlying cause persists 1,4,6.

Types of Onycholysis

Onycholysis is not a one-size-fits-all condition. Recognizing the different types helps tailor diagnosis and treatment strategies.

Type	Description	Typical Trigger	Source
Simple	Distal separation, no underlying disease	Trauma, irritants	6,13
Photo-onycholysis	Half-moon separation, phototoxic	UV + drugs (tetracyclines)	3,7,8,9
Disease-related	Linked to systemic or skin disease	Psoriasis, thyroid, etc.	1,4,13
Mechanical	Pressure-induced, often in toenails	Tight shoes, flat feet	4

Table 2: Types of Onycholysis

Simple Onycholysis

This is a diagnosis of exclusion—meaning it's made when no other underlying medical condition is found. It's usually the result of repetitive trauma or chronic exposure to moisture and irritants. Simple onycholysis is most common in fingernails and often troubles patients mainly for cosmetic reasons 6,13.

Photo-onycholysis

A fascinating subtype, photo-onycholysis, occurs when certain medications (notably tetracyclines, psoralens, and some chemotherapy agents) make the nail sensitive to ultraviolet light. This results in a characteristic half-moon shaped separation, often with distinctive discoloration 3,7,8,9. Spontaneous cases have also been described following sun exposure alone 8.

• Subtypes by shape:
  • Half-moon (Type I)
  • Circular notch (Type II)
  • Central separation (Type III) 3

Disease-Related Onycholysis

This form is associated with systemic diseases such as hyperthyroidism, psoriasis, or fungal nail infections (onychomycosis). It may be the first sign of an underlying condition and is often accompanied by other nail or skin changes 1,4,13.

• Psoriasis: Up to 90% of patients may develop nail changes, with onycholysis being exceedingly common 13.
• Hyperthyroidism: Plummer’s nails are a classic example 1.
• Onychomycosis: Fungal infection often causes thickening and discoloration as well 12.

Mechanical Onycholysis

Most frequently seen in toenails, this type is caused by chronic pressure—typically from ill-fitting, closed shoes or from an abnormal gait that increases mechanical stress on certain toes 4.

Causes of Onycholysis

Pinpointing the cause of onycholysis is crucial for effective management. The range is broad—from every day habits to serious medical illnesses.

Cause	Mechanism/Trigger	Typical Nails Affected	Source
Trauma	Physical injury, manicuring	Fingers, toes	4,5,6
Irritants/Moisture	Chemicals, frequent wetting	Fingers	6,13
Infections	Fungi (dermatophytes, Candida), bacteria	Toes, fingers	4,12
Systemic diseases	Psoriasis, hyperthyroidism	Fingers mostly	1,4,13
Medications	Chemotherapy, antibiotics	Any	3,7,9,14
Ultraviolet exposure	Sunlight, especially with drugs	Fingers	3,7,8,9
Nutritional deficiencies	Iron, vitamins	Any	2
Tumors	Nail bed neoplasms	Single nail	5,6
Mechanical pressure	Tight shoes, abnormal gait	Toes	4

Table 3: Causes of Onycholysis

Physical and Chemical Trauma

The most common cause is repeated trauma—whether from aggressive manicuring, frequent tapping, or even job-related use of hands. Nail cosmetics, harsh detergents, and prolonged moisture exposure can all weaken the nail bond 4,6,13.

Infections

• Fungal (Onychomycosis): Dermatophytes and Candida species are frequently isolated, though Candida’s role as a direct cause is debated 4,12.
• Bacterial: Pseudomonas and other bacteria can colonize the space beneath the lifted nail, especially when moisture is present 4.

Systemic and Dermatologic Diseases

• Psoriasis: Causes parakeratosis of the hyponychium, leading to loss of nail adherence 13.
• Hyperthyroidism: Thyrotoxic catabolism and rapid nail growth contribute to separation (Plummer’s nails) 1.
• Other diseases: Sarcoidosis, lung cancer, and others are less frequent but possible causes 1.

Medications and Phototoxicity

Certain drugs sensitize the nail to ultraviolet light, causing phototoxic onycholysis. Notable culprits include:

• Tetracyclines (e.g., doxycycline): Well-known for causing photo-onycholysis, especially after sun exposure 3,9.
• Chemotherapy agents: Taxanes (docetaxel, paclitaxel) and anthracyclines 7,10.
• Targeted cancer therapies: Such as erdafitinib 14.

Nutritional and Other Factors

Iron and other vitamin deficiencies may contribute, especially in cases where no other cause is found 2. Occasionally, nail bed tumors or neoplasms lead to persistent, single-nail onycholysis 5,6.

Treatment of Onycholysis

Effective treatment of onycholysis requires a multifaceted approach. Success depends on addressing the underlying cause, preventing secondary infection, and protecting the nail as it regrows.

Treatment	Approach/Mechanism	Indication	Source
Irritant avoidance	Reduce trauma, moisture, chemicals	All types	6,13
Nail care	Clip back to point of attachment	All types	6
Topical antifungals	E.g., efinaconazole, ciclopirox	Onychomycosis	6,12
Oral antifungals	Fluconazole (if Candida present)	Recalcitrant cases	6
Topical steroids	Calcipotriol + betamethasone	Suspected psoriasis	13
Hydrating nail solutions	EVONAIL®, etc.	Chemotherapy-related	10
Laser therapy	Nd:YAG 1064 nm laser	Traumatic onycholysis	11
Sun protection	Avoid UV exposure during treatment	Photo-onycholysis, chemo	7,9
Address underlying disease	Treat thyroid, psoriasis, etc.	Disease-related	1,13

Table 4: Treatment Approaches

General Principles

Irritant and Moisture Avoidance

• Protect nails from further trauma.
• Minimize exposure to water and harsh chemicals (e.g., detergents, nail polish remover) 6,13.
• Dry the affected area thoroughly—using a hair dryer is recommended to reduce moisture and discourage microbial growth 4.

Nail Care

• Trim the nail back to the point where it is still attached to prevent further detachment and reduce the risk of snagging or trauma 6.
• Avoid nail cosmetics and artificial nails until the nail has fully recovered, usually for about a month after normalization 6.

Specific Treatments

Fungal and Infectious Causes

• Topical antifungals: Efinaconazole 10% solution is effective for mild-to-moderate onychomycosis and offers high nail bed penetration 12.
• Oral antifungals: Such as fluconazole, may be required in recalcitrant or severe cases, particularly when Candida is proven 6.
• Antibacterial care: If bacterial colonization (e.g., Pseudomonas) is evident, keeping the area dry is vital. Antibiotics are rarely needed 4.

Disease-Related Onycholysis

• Psoriasis: Topical steroids (calcipotriol and betamethasone) under occlusion may improve nail adherence 13.
• Hyperthyroidism: Treating the underlying thyroid disorder leads to significant improvement and regrowth of normal nails 1.

Drug and Photo-induced Onycholysis

• Discontinue or substitute the offending medication if possible 9,14.
• Strict avoidance of sun or UV exposure during and after therapy is crucial to prevent further episodes 7,9.

Chemotherapy-associated Onycholysis

• Hydrating nail solutions: Prophylactic application can significantly reduce severity and incidence 10.
• Nail protection: Minimize trauma and avoid excess exposure to sunlight during chemotherapy 7.

Physical Therapies

• Laser therapy: Early studies suggest Nd:YAG 1064 nm lasers may hasten recovery in traumatic onycholysis, though more research is needed 11.

When to Seek Specialist Care

• Persistent or worsening onycholysis despite conservative management.
• Signs of infection: pain, swelling, pus, or severe discoloration.
• If only a single nail is affected and a tumor is suspected, biopsy may be indicated 6.

Conclusion

Onycholysis is a multifaceted nail disorder that often reflects underlying trauma, infection, systemic disease, or environmental exposures. Recognizing the symptoms and types of onycholysis helps guide appropriate investigations and management. With proper care and attention to the root cause, most cases can be effectively treated.

Key points:

• Onycholysis involves painless separation of the nail plate from the nail bed, often with discoloration or dirt accumulation.
• Types include simple, photo-induced, disease-related, and mechanical, each with distinct triggers and patterns.
• Common causes range from trauma and fungal infections to systemic diseases and medications.
• Treatment focuses on eliminating the cause, protecting the nail, and, when needed, using antifungal, steroid, or hydrating therapies.
• Persistent or unusual cases require specialist evaluation to rule out underlying disease or neoplasm.

Stay vigilant—if your nails start to lift, look beyond the surface. Early intervention can restore both health and confidence.