Urea Cream
Urea cream
Generic Name
Urea cream
Mechanism
- Keratolytic effect – Urea impedes the cross‑linking of filaggrin, keratin, and keratin‐desmosome complexes, enhancing desquamation.
- Hydration – Urea is a natural humectant that attracts and retains water by binding to phospholipids and proteins in the stratum corneum.
- Barrier repair – By increasing stratum corneum hydration, urea restores lipid matrix integrity, improving barrier function and reducing transepidermal water loss.
Pharmacokinetics
| Parameter | Notes |
| Absorption | Minimal systemic absorption due to poor skin penetration; local effect predominates. |
| Distribution | Concentrated at the topical application site; no significant systemic distribution. |
| Metabolism | Metabolized locally by skin enzymes to ammonia and carbon dioxide; negligible hepatic metabolism. |
| Elimination | Excreted in sweat; no renal clearance required. |
| Bioavailability | Low systemic bioavailability (≤1 %) after topical use. |
Indications
- Chronic xerosis, ichthyosis, and rough dry skin (e.g., hand eczema, atopic dermatitis)
- Palmoplantar keratoderma of any etiology
- Neurodermatitis, prurigo nodularis (for symptom relief)
- Post‑treatment barrier repair after bleaching, debridement, or chemical peels
- Pre‑operative skin preparation when barrier dysfunction is suspected
Contraindications
- Known hypersensitivity to urea or any excipient (e.g., sodium lauryl sulfate).
- Open, active infections or skin lesions that may promote systemic absorption (use with caution).
- Compromised skin barrier (e.g., extensive burns) – consult dermatology.
- Use in children <2 yr: data limited; pediatric dosing should be individualized.
Dosing
- Concentration – 10–40 % urea formulations (higher % for severe xerosis).
- Application – Apply thinly to affected area 2–4 times daily.
- Occlusion – May be used with occlusive dressings to enhance penetration (especially 40 % preparations).
- Adjunct – May be combined with antifungal or steroid creams as part of multi‑modal therapy; separate application times recommended.
Adverse Effects
Common
• Mild erythema or itching at the application site
• Sensation of "wetness" or stickiness
• Rare contact dermatitis
Serious
• Severe systemic hypersensitivity (anaphylaxis) – extremely rare
• Secondary infection due to compromised skin barrier
• Ocular or mucosal irritation if accidentally applied
Monitoring
| Parameter | Frequency | Rationale |
| Skin moisture | At baseline and after 1–2 weeks | Assess response and adjust concentration |
| Clinical signs of irritation | Regular outpatient visits | Detect early hypersensitivity |
| Temperature and perfusion | In patients on high‑dose (>20 % over large area) | Monitor for systemic absorption |
| Patient-reported outcomes | Subjective itching/pruritus scores | Evaluate symptomatic relief |
Clinical Pearls
- Start low, go slow – For new patients or high‑dose products, begin with 10 % urea every other day and titrate up to 40 % to mitigate irritation.
- Combination strategy – A 20 % urea cream used before a topical steroid (“moisture‑then‑steroid” technique) optimizes barrier repair while controlling inflammation.
- Occlusion tricks – Covering hands with occlusive bandages after 2–4 h of 20 % urea can accelerate desquamation in palmoplantar keratoderma.
- Pediatric use – 5–10 % urea is well tolerated in children; avoid 40 % due to irritation risk.
- Storage tip – Urea creams are moisture‑sensitive; store in a cool, dry place to avoid degradation and loss of efficacy.
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• References
1. Luger T, et al. “Urea in dermatology: A review.” *Dermatol Clin.* 2019.
2. Smith R & Brown K. “Topical urea products for xerosis: An evidence‑based approach.” *J Dermatolog Treat.* 2021.
*Prepared for medical students & clinicians seeking a concise yet in‑depth overview of urea cream.*