Urea: a comprehensive review of the clinical literature.

Introduction: Urea is an organic compound that has been used clinically for dermatological diseases for more than a century. Urea is a potent emollient and keratolytic agent, making urea an effective monotherapy for conditions associated with dry and scaly skin. A systematic review of the literature is needed to provide clinicians with evidence-based applications of urea in the treatment of dermatological diseases.

Methods: A PubMed search was conducted using the term "urea" combined with "skin," "ichthyosis," "psoriasis," "xerosis," "emollient," "onychomycosis," "dermatitis," and "avulsion." A total of 81 publications met inclusion criteria and were evaluated. Treatment indication(s), test agents, number of subjects, treatment protocols, results, and side effects were recorded.

Results: Effective treatment with urea has been reported for the following conditions: ichthyosis, xerosis, atopic dermatitis/eczema, contact dermatitis, radiation induced dermatitis, psoriasis/seborrheic dermatitis, onychomycosis, tinea pedis, keratosis, pruritus, and dystrophic nails. Furthermore, urea has been used with other medications as a penetration enhancing agent. Mild irritation is the most common adverse event, proving urea to be a safe and tolerable topical drug without systemic toxicity.

Discussion/conclusion: Urea is a safe, effective dermatologic therapy with wide-ranging clinical utility and minimal, non-systemic side effects. In order to optimize patient care, dermatologists should be well informed with regards to urea's indications and efficacy.