Urea cream for nails

How is 40% urea used to treat fungal infections of the toe nail?

What is urea and why does it help to treat fungal nail infections?

Urea debridement of mycotic nails – safe, easy and effective.

Urea, also known as carbamide, is an organic chemical compound that was first synthesized in 1828. Urea is often referred to as one of the most basic and important chemicals used in healthcare today. In addition to medical uses, urea is used as a resin in making plywood, as an adjunct in animal feed and is actually used as the main ingredient that makes pretzels their distinctive brown color. (1)

Urea’s primary uses though are in medicine. Urea is used in skin preparation to soften keratin, treating psoriasis, eczema, and corns and calluses. Urea is particularly helpful in treating thick, dystrophic fungal (onychomycosis) nails. 40% urea effectively debrides the diseased nail while leaving healthy nail intact and unaffected.

In the early years of my podiatry practice, I would follow a chemical recipe from the Russian literature to make a 40% urea preparation for my patients to use to treat thick, mycotic nails. With the help of our in-house skin care team (Myfootshop.com’s Natural’s line of products), we’ve formulated a 40% urea paste we call Natural Antifungal Nail Butter. To treat the fungal infection of the nail, we’ve also added tea tree oil and lavender to naturally treat fungal nail infections.

I want to stress that Natural Antifungal Nail Butter with 40% urea is intended to treat fungal nail infection, but more importantly, the 40% urea is intended to debride diseased nail. The images below show two stages of a fungal nail infection. On the left, the image shows an early infection. This nail is easily treated with a topical antifungal like Terpenicol or Clearzal. The nail on the right will require both mechanical and chemical debridement. In this case, the use of a nail cutter and Nail Butter with 40% urea is indicated.

1. https://en.wikipedia.org/wiki/Urea


Jeffrey A. Oster, DPM

Medical Advisor

Updated 12/24/19

Medical nail avulsion

What is medical nail avulsion?

Medical nail avulsion is the removal of a fingernail or, more often, a toenail by chemical destruction of the nail plate. It is a painless process that takes several weeks to complete.

Nails can also be partly or completely removed by:

  • Surgical nail avulsion
  • Trauma.

These more aggressive processes are painful and may lead to permanent nail dystrophy.

Who gets medical nail avulsion?

Medical nail avulsion is used to remove a nail that is causing symptoms that have not improved by other means. Examples include:

  • Complete nail destruction due to fungal infection
  • Thickened nail (onychogryphosis) due to any cause, eg congenital, ageing, tight shoes, psoriasis
  • Ingrown nail (onychocryptosis).

What chemical is used for medical nail avulsion?

The main ingredient of a medical nail avulsion preparation is 40% urea. The urea is compounded with various other ingredients to make a suitable formulation that slowly macerates the nail plate. A typical 30-g formulation used for chemical nail avulsion is listed here.

  • Urea 40%
  • White wax 5%
  • Anhydrous lanolin 20%
  • White petrolatum 35%

Urea is also used in a lower concentration to remove scale and soften dry skin.

How is medical nail avulsion undertaken?

  1. Clip back and pare down the nail so it is as short and thin as possible
  2. Protect surrounding skin: apply tincture of benzoin then zinc oxide tape to the nail folds
  3. Apply the urea preparation to exposed nail and bed
  4. Cover with occlusive tape dressing
  5. Keep the treated area clean and dry

In one week, remove the occlusive tape dressing, gently pare away the soft tissue, wash the digit and nail using antiseptic or saline, and repeat steps 1 to 4 above.

Once all the diseased or thickened nail plate has been removed after 3 to 6 weeks, the dressings can be removed and the chemical nail avulsion has been completed. Protect the nail bed from injury, especially initially. A protective layer of skin will grow over the nailbed within a few weeks.

Topical and/or oral antifungal treatment can be used before, during, and after chemical nail avulsion, if there is a fungal nail infection (onychomycosis)

Complications of medical nail avulsion

Secondary bacterial infection is the main risk, but is uncommon.

Allergic contact dermatitis may arise due to the use of tincture of benzoin, which contains the allergen balsam of Peru, and zinc oxide tape, which contains the allergen colophony/rosin. In this case, alternative adhesive preparations may be used.

What is the outlook for medical nail avulsion?

Medical nail avulsion is not completely successful at curing fungal nail infection, as fungi may be growing in the nail matrix under the proximal nail fold. This will be obvious as the nail begins to grow out again. Nor is it effective treatment for an inflammatory nail disease such as psoriasis.

In a healthy young adult, regrowth of a fingernail is expected to take around 9 months. It takes about 18 months to fully grow a great toenail. Nail growth may be slower in older individuals or in people with poor circulation.

The process can be repeated at a later date if desired.

Medically reviewed by Drugs.com on May 17, 2019 – Written by Cerner Multum

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What is Urea Nail Gel?

There are many brands and forms of urea topical available and not all brands are listed on this leaflet.

Urea Nail Gel (for the skin) is used to soften rough or dry skin caused by skin conditions such as eczema, psoriasis, keratosis, and others. This medicine is also used to soften damaged fingernails or toenails so they can be removed without surgery.

Urea Nail Gel may also be used for purposes not listed in this medication guide.

Important Information

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use Urea Nail Gel if you are allergic to it.

FDA pregnancy category C. It is not known whether Urea Nail Gel will harm an unborn baby. Do not use Urea Nail Gel without a doctor’s advice if you are pregnant.

It is not known whether urea topical passes into breast milk or if it could harm a nursing baby. Do not use this medicine without a doctor’s advice if you are breast-feeding a baby.

How should I use Urea Nail Gel?

Urea Nail Gel is available in many different forms (cream, lotion, ointment, liquid, gel, foam, shampoo, and others) for use on the skin or the scalp. Use your medicine exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Do not take by mouth. Urea Nail Gel is for use only on the skin. If this medication gets in your eyes, nose, mouth, rectum, or vagina, rinse with water.

Use a mild soap or cleanser to wash the skin or nail area to be treated. Urea Nail Gel may work best if the skin or nail to be treated is left slightly damp before the medicine is applied.

Apply a thin layer of this medicine to the affected skin and rub it in as completely as possible.

When applying Urea Nail Gel to the nails, avoid getting any medicine on the cuticles or surrounding skin. Apply generously to the nail and allow the medicine to dry. You may cover the nail with a bandage or gauze if your doctor advises. The treated nail should be easily removed after several days.

Shake the Urea Nail Gel foam well just before each use. Other forms of this medicine may also need to be shaken before use. Follow all directions on th medicine label.

Wash your hands with soap and water after applying this medicine, unless you are treating the skin on your hands.

Call your doctor if your symptoms do not improve, or if they get worse while using Urea Nail Gel.

Store at room temperature away from moisture and heat. Do not freeze. Keep the medicine container tightly closed when not in use.

Keep the foam canister away from open flame or high heat. The canister may explode if it gets too hot. Do not puncture or burn an empty foam canister.

What happens if I miss a dose?

Use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Urea Nail Gel?

Do not use Urea Nail Gel on open wounds, burns, or areas of swollen skin. If this medication gets in your eyes, nose, mouth, rectum, or vagina, rinse with water.

Urea Nail Gel side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using Urea Nail Gel and call your doctor at once if you have:

  • severe redness or irritation of treated skin.

Common side effects may include:

  • mild itching; or

  • mild burning or stinging.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Urea Nail Gel?

It is not likely that other drugs you take orally or inject will have an effect on topically applied urea. But many drugs can interact with each other. Tell each of your health care providers about all medicines you use, including prescription and over-the-counter medicines, vitamins, and herbal products.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2018 Cerner Multum, Inc. Version: 1.02.

Medical Disclaimer

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Therapy for Onychomycosis
In a randomized, double-blind study of 70 patients with onychomycosis of the finger and toenails. The results indicated topical treatment of onychomycosis with a combination of fluconazole 1% and urea 40% was more effective (82.8%) than fluconazole 1% nail lacquer (62.8%) alone in treatment of onychomycosis. Fluconazole was well tolerated and side effects were negligible.
J Dermatolog Treat. 2012 Dec;23(6):453-6.
A comparative evaluation of combination therapy of fluconazole 1% and urea 40% compared with fluconazole 1% alone in a nail lacquer for treatment of onychomycosis: therapeutic trial.
to access the PubMed abstract of this article.
Treatment of Fingernail Lichen Planus
Nail lichen planus most commonly occurs during the fifth and sixth decade of life and can be notoriously recalcitrant to many forms of treatment. Prevost and English of the University of Pittsburgh Department of Dermatology reported a case of successful treatment of destructive inflammatory lichen planus of the nails with combined topical therapy of tazarotene gel and clobetasol gel, without the occurrence of potential adverse affects of systemic treatments.
J Drugs Dermatol. 2007 Feb;6(2):202-4.
Palliative treatment of fingernail lichen planus.
to access the PubMed abstract of this article.
Although surgical excision is the most popular method for removing nails, the use of concentrated urea plasters applied under occlusion may be superior. The use of urea plasters has inherent advantages – they are inexpensive, several nails can be treated in one session, and the procedure is essentially painless. Various synergistic combinations and topical medications with penetrant enhancers can be compounded for antifungal therapy. Topical medications usually have a lower adverse drug-reaction profile than systemic medications.
IJDVL 2012; 78(3):299-308
Nail avulsion: Indications and methods (surgical nail avulsion)
to read the reference article.
Cutis. 1980 Jun;25(6):609-12
Urea ointment in the nonsurgical avulsion of nail dystrophies–a reappraisal.
to access the PubMed abstract of this article.
Cutis. 1980 Apr;25(4):397, 405
Combination urea and salicyclic acid ointment nail avulsion in nondystrophic nails: a follow-up observation.
to access the PubMed abstract of this article.
JAMA 1979 Apr 13;241(15):1559, 1563
Urea plasters alternative to surgery for nail removal.
PMID: 430701 (No abstract available)
Clin Exp Dermatol 1982 May;7(3):273-6
The treatment of fungus and yeast infections of nails by the method of “chemical removal”.
PMID: 7105479 (No abstract available)
Management of onychomycosis, a fungal infection of the fingernails and toenails, usually consists of systemic antifungal medications, topical therapy (e.g., urea ointment, desiccating solutions, keratolytics, vital dyes), or surgical intervention (e.g., nail plate avulsion, laser therapy). Topical prescription antifungal preparations, containing the active ingredient of your choice, may be less likely to cause the serious systemic side effects that can occur with oral antifungal therapy and can provide a more economical alternative, as lower doses are needed when the medication is applied topically at the site. Penetrant enhancers can be included in the preparation to improve the effectiveness of topical antifungals. Trop Med Int Health 1999 Apr;4(4):284-7
Treatment of toenail onychomycosis with 2% butenafine and 5% Melaleuca alternifolia (tea tree) oil in cream.
to access the PubMed abstract of this article.

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