Onycholysis

Onycholysis is characterized by a spontaneous separation of the nail plate starting at the distal free margin and progressing proximally. In onycholysis, the nail plate is separated from the underlying and/or lateral supporting structures. Less often, separation of the nail plate begins at the proximal nail and extends to the free edge, which is seen most often in psoriasis of the nails (termed onychomadesis). Rare cases of onycholysis are confined to the nail's lateral borders. Treatments may include topical or intralesional corticosteroids, pulsed-dye laser, or psoralen plus ultraviolet A (PUVA) light.

See the images below.

Nails with onycholysis usually are smooth, firm, and without inflammatory reaction. Onycholysis is not a disease of the nail matrix, but nail discoloration may appear underneath the nail as a result of secondary infection. When onycholysis occurs, a coexistent yeast infection is suggested. Treating primary and secondary factors that exacerbate onycholysis is important. Left untreated, severe cases of onycholysis may result in nail bed scarring.

Endogenous, exogenous, hereditary, and idiopathic factors can cause onycholysis. Contact irritants, trauma, and moisture are the most common causes of onycholysis, but other associations exist.

Endogenous factors in onycholysis

Systemic diseases and states in onycholysis are as follows:

• Amyloid and multiple myeloma

• Anemia (iron deficient)

• Bronchiectasis

• Diabetes mellitus

• Erythropoietic porphyria

• Histiocytosis X

• Hyperthyroidism ^[1]

• Hypothyroidism

• Ischemia (peripheral, impaired circulation)

• Leprosy

• Lupus erythematosus

• Neuritis

• Pellagra

• Pemphigus vulgaris

• Pleural effusion

• Porphyria cutanea tarda

• Pregnancy

• Psoriatic arthritis

• Reiter syndrome

• Sarcoidosis

• Scleroderma

• Shell nail syndrome

• Syphilis

• Yellow nail syndrome

Dermatologic diseases in onycholysis are as follows:

• Psoriasis

• Lichen planus

• Dermatitis

• Hyperhidrosis

• Pachonychia congenita

• Congenital ectodermal defect

• Pemphigus vegetans

• Lichen striatus

• Atopic dermatitis

• Congenital abnormalities of the nail

Neoplastic disorders in onycholysis are as follows:

• Squamous cell carcinoma (of nail bed)

• Carcinoma (lung)

Exogenous factors in onycholysis

Nonmicrobial factors in onycholysis (may be encountered at the job site, ie, as occupational onycholysis) are as follows:

• Mechanical - Mechanical force (trauma), repetitive minor trauma, or maceration

• Chemical - Allergic or irritant contact dermatitis from various nail cosmetics (methyl methacrylate monomer, formaldehyde 1-2%, nail base coat/hardeners, polymerized 2-ethylcyanoacrylate adhesive used in artificial nails, nail lacquer), ^[2] gasoline, paint removers, dicyanodiamide, thioglycolate, solvents, and hydroxylamine sulphate in color developer

• Chemical - Irritant contact dermatitis from prolonged immersion of nails in water, sugar onycholysis in confectioners/bakers, and exposure to highly destructive toxins (eg, hydrofluoric acid)

Biologic/microbial factors are as follows:

• Dermatophytosis (ie, Trichophyton rubrum, Trichophyton mentagrophytes infection)

• Yeast (Candida infection)

• Bacteria (Pseudomonas infection)

• Virus (herpes simplex infection)

Drug associations with onycholysis

Photo-induced associations, with medication and subsequent exposure to sunlight, are as follows:

• Tetracycline and its derivatives

• Psoralens

• Fluoroquinolones

• Chloramphenicol

• Benoxaprofen

• Chlorpromazine

• Chlortetracycline

• Demethylchlortetracycline

• Doxycycline ^{[3, 4]}

• Minocycline ^[5]

• Oral contraceptives

• 5-Methoxypsoralen (Psoraderm 5)

• Aminolevulinic acid (from phototherapy) ^[6]

• Olanzapine ^[7]

• Aripiprazole ^[7]

• Griseofulvin ^[8]

Photo-induced associations with onycholysis, without medication and exposure to sunlight, are as follows:

• Spontaneous photo-onycholysis ^[9]

• Bullous photo-onycholysis (during pseudoporphyria resulting from hemodialysis)

Non-photo–induced associations with onycholysis ^[10] are as follows:

• Doxorubicin

• Mitoxantrone

• Captopril

• Bleomycin

• 5-Fluorouracil (capecitabine) ^{[11, 12]}

• Retinoids

• Tetracycline

• Etoposide

• Paclitaxel ^[13]

• Docetaxel ^{[13, 14]}

• Hydroxylamine

Other factors in onycholysis

These include the following:

• Congenital onycholysis

• Hereditary partial onycholysis

• Idiopathic acquired onycholysis

• Hereditary distal onycholysis ^[15]

• Foreign body implantation

Frequency

The worldwide incidence of onycholysis is unknown.

Race

Distribution of onycholysis by race is unknown; however, onycholysis has been observed in persons of all races.

Sex

Individuals of either sex can have onycholysis; however, studies demonstrate an overwhelmingly female predilection.

Age

People of any age can present with onycholysis, although it primarily is a disease of adulthood.

Severe cases of onycholysis that are left untreated may result in nail bed scarring.

Educate patients with onycholysis about avoiding possible contact irritants, trauma, and moisture.

For patient education resources, see the Skin Conditions & Beauty Center and the patient education articles Nail Psoriasis and Onychomycosis.