Medication Summary
In onycholysis, apply a topical antifungal imidazole or allylamine twice daily to avoid superinfection of the nail. An oral broad-spectrum antifungal agent (ie, fluconazole, itraconazole, terbinafine) may be used for cases with concomitant onychomycosis.
Midstrength topical corticosteroids are suitable for isolated onycholysis. High-potency topical steroids (eg, clobetasol ointment) under occlusion have been used with less than ideal results for patients with severe nail dystrophy unwilling to undergo intralesional injection of corticosteroids. Patients follow this regimen for 2 weeks and then discontinue use of topical steroids for 2 weeks to avoid the other local adverse effects of topical steroids.
Massaging 5-fluorouracil 1% solution twice a day into the proximal nail fold for 4 months has been effective for patients with nail pitting and hyperkeratosis from psoriasis. Application to the free end of the nail should be avoided, as this will cause onycholysis. Localized PUVA, oral etretinate, hydroxyurea, and isotretinoin are other agents that have had some success in treating onycholysis resulting from psoriasis.
Treatment is not without adverse effects. They may include subungual hematoma secondary to intralesional steroid injections and photo hemolysis secondary to PUVA treatment. Explain risks to patients before initiating therapy.
Antifungals
Class Summary
Antifungals treat superinfection of the onycholytic nail by dermatophytic molds and/or candidal yeasts.
Clotrimazole (Mycelex, Lotrimin)
Clotrimazole is a broad-spectrum antifungal agent that inhibits yeast growth by altering cell membrane permeability, causing the death of fungal cells.
Econazole topical (Ecoza)
Econazole is effective in cutaneous infections. It interferes with RNA and protein synthesis and metabolism. Econazole disrupts fungal cell wall membrane permeability, causing fungal cell death.
Ketoconazole topical (Nizoral)
Ketoconazole is an imidazole broad-spectrum antifungal agent; it inhibits the synthesis of ergosterol, causing cellular components to leak, resulting in fungal cell death.
Fluconazole (Diflucan)
Fluconazole is a synthetic oral antifungal (broad-spectrum bistriazole) that selectively inhibits fungal cytochrome P450 and sterol C-14 alpha-demethylation.
Itraconazole (Sporanox)
Itraconazole has fungistatic activity. It is a synthetic triazole antifungal agent that slows fungal cell growth by inhibiting cytochrome P-450-dependent synthesis of ergosterol, a vital component of fungal cell membranes.
Terbinafine (Lamisil)
Terbinafine was the first oral allylamine antimycotic agent to be released, having a different mode of action than the azoles. It is considered to be fungicidal, rather than fungistatic. It inhibits the enzyme squalene epoxidase in the sterol synthesis pathway.
Corticosteroids
Class Summary
Corticosteroids treat noninfectious causes of onycholysis. They have anti-inflammatory properties and cause profound and varied metabolic effects. Corticosteroids modify the body's immune response to diverse stimuli. Intralesional and topical corticosteroids are designed to treat any noninfectious inflammatory condition associated with onycholysis with minimal risk for systemic absorption.
Triamcinolone (Aristocort)
Triamcinolone is used for inflammatory dermatosis responsive to steroids. It decreases inflammation by suppressing the migration of polymorphonuclear leukocytes and reversing capillary permeability.
Clobetasol (Temovate)
Clobetasol is a class I superpotent topical steroid; it suppresses mitosis and increases synthesis of proteins that decrease inflammation and cause vasoconstriction.
Pyrimidine antagonists, topical
Class Summary
Topical pyrimidine antagonists inhibit cell growth and proliferation. Their mechanism is unknown for treating onycholysis. They are reported to be effective in the treatment of nail pitting and onycholysis associated with psoriasis.
Fluorouracil topical (Fluoroplex)
Fluorouracil is a fluorinated pyrimidine analog used in topical form to treat actinic keratoses. It has an unknown mechanism in treating onycholysis. Use 1% solution.
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Thumb onycholysis. Courtesy of DermNet New Zealand (http://www.dermnetnz.org/assets/Uploads/hair-nails-sweat/olysis1.jpg).
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Great toe onycholysis. Courtesy of Professor Raimo Suhonen and DermNet New Zealand (http://www.dermnetnz.org/assets/Uploads/hair-nails-sweat/s/olysis7.jpg).
