Emollients & Moisturisers
Summary
Emollients are medical moisturisers that soothe, hydrate, and protect the skin. They are the cornerstone of therapy for all dry skin conditions (Eczema, Psoriasis, Ichthyosis). They work by:
- Occlusion: Trapping moisture in.
- Repair: Replacing lost skin lipids.
- Humectant: Drawing water into the stratum corneum (e.g., Urea). Proper use reduces the need for topical steroids ("Steroid Sparing"). [1,2]
Clinical Pearls
The Fire Risk: Any emollient containing >50% paraffin is highly flammable. Wait... actually, ALL emollients (even paraffin-free ones) can act as an accelerant if they soak into fabric (clothes, dressings, bedding). Patients smoking in bed covered in emollient residue have died from rapid combustion. Valid warnings are mandatory.
Direction of Hair Growth: Always apply emollient downwards (with the hair). Rubbing up/circularly forces grease into the follicle, causing Folliculitis.
Soap Substitute: Soap destroys the skin barrier. Patients with eczema should NEVER use soap or shower gel. They should use their emollient to wash with. It puts oils IN while washing dirt OFF.
Indications
- Eczema (Atopic Dermatitis): First line. Maintenance.
- Psoriasis: Scaling reduction.
- Xerosis: Dry skin of unknown cause.
- Ichthyosis: Genetic dry skin.
Burden
- Under-prescribed. A typical adult with generalized eczema needs 500g per week. Prescribing a 50g tube is a clinical error.
Mechanisms
- Occlusives (Petrolatum, Dimethicone): Form a hydrophobic layer preventing Transepidermal Water Loss (TEWL).
- Humectants (Urea, Glycerol, Lactic Acid): Small molecules that penetrate the stratum corneum and attract water molecules.
- Emollients: Fill the spaces between desquamating corneocytes, smoothing the surface.
| Type | Oil:Water | Examples | Pros | Cons |
|---|---|---|---|---|
| Lotion | Low Oil / High Water | E45 Lotion, Aveeno Lotion | Evaporates fast. Cooling. | Poor moisturiser. Can sting. |
| Cream | Balanced | Cetraben, Zerobase, Epaderm Cream | Cosmetically acceptable. Absorbs well. | Contains preservatives (sting/allergy). |
| Gel | High Glycerol | Doublebase, Isomol | Humectant rich. Less greasy than ointment. | Can be sticky. |
| Ointment | High Oil (No Water) | Epaderm Oint, Hydromol, 50:50 WSP | Most effective. Preservative free (rarely stings). | Greasy, Messy, Stains clothes. |
Problems
- Stinging: Common with creams (preservatives like Benzyl alcohol) or Urea (on broken skin). Switch to Ointment.
- Folliculitis: Pustules at hair follicles. Due to heavy grease blocking pores. Switch to Cream/Lotion or correct application technique.
- Slipping: Bath additives make the bath like an ice rink. Warning required for elderly.
Choosing the Right Emollient
- There is no "best" emollient.
- The best one is the one the patient will actually use.
- Trial and error is standard practice. Give small samples of 3 types (Light, Medium, Heavy) and let the patient decide.
Management Algorithm (Application)
PRESCRIBE EMOLLIENT
(Aim for 500g/week for adults)
↓
APPLICATION TECHNIQUE
1. Scoop out wih CLEAN HANDS / SPOON
(Do not put dirty finger in tub)
2. Dot onto skin
3. Stroke DOWNWARDS (With hair)
(Do NOT rub in circles)
4. Wait for it to soak in
(Leave a glistening layer)
↓
WHEN TO APPLY
- At least TWICE daily
- Immediately AFTER bathing ("Soak and Seal")
(Traps the hydration from the bath)
- Whenever skin feels dry/itchy
↓
USE AS SOAP SUBSTITUTE
- Mix with water in palm to make lather
- Apply to body
- Rinse off
- Pat dry (do not scrub)
1. Wait time with Steroids
- If using topical steroids, apply the emollient first.
- Wait 30 minutes.
- Then apply the steroid.
- Rationale: If applied together, the emollient dilutes the steroid and spreads it to areas that don't need it.
2. Pump Dispensers vs Tubs
- Pump: Better hygiene (prevents Staph aureus colonization of the pot).
- Tub: Cheaper. If using a tub, use a spoon or spatula to extract cream.
- Fire: Clothing/Bedding saturated with paraffin residue can catch fire easily.
- Infection: Contaminated pots causing recurrent cellulitis/impetigo.
- Allergy: Lanolin (Wool fat) or preservative allergy.
- Regular use restores barrier function, reduces itch, and significantly prolongs the time between flares of eczema.
- It is a lifelong treatment for atopic patients.
Key Guidelines
| Guideline | Organisation | Key Recommendations |
|---|---|---|
| Atopic Eczema | NICE CG57 | Use large quantities (250-500g/week). Use as soap substitute. |
| Fire Safety | MHRA | Warning on all paraffin-based products. |
Landmark Evidence
1. COMET Study
- Compared 4 types of emollients. Found no difference in effectiveness between creams, gels, and ointments. The only predictor of success was patient satisfaction/preference.
What are emollients?
They are medical moisturizers. Unlike cosmetic creams (which smell nice but are thin), emollients are designed to repair the damaged skin barrier.
How often should I use them?
As much as possible. You cannot overdose. For eczema, think of it like painting a wall - apply a thick layer frequently.
Can I use soap?
No. Soap strips the natural oils from your skin. Use your emollient as a soap substitute. It won't bubble, but it cleans you perfectly well without drying you out.
Is it dangerous?
Be careful near open fires (candles/cigarettes) as the cream can soak into clothes and burn easily. Also, be careful in the bath - it makes the surface very slippery.
Primary Sources
- NICE. Atopic eczema in under 12s: diagnosis and management (CG57). 2007.
- Ridd MJ, et al. Effectiveness and safety of lotion, cream, gel, and ointment emollients for childhood eczema: a pragmatic, randomised, phase 4, superiority trial (BATHE). Lancet Child Adolesc Health. 2022.
Common Exam Questions
- Usage: "How much to prescribe?"
- Answer: 500g per week (Adult).
- Safety: "Major risk?"
- Answer: Fire hazard.
- Technique: "Direction of application?"
- Answer: With hair growth (to avoid folliculitis).
- Pharmacology: "Preservative free option?"
- Answer: Ointment (e.g., 50:50 White Soft Paraffin).
Viva Points
- Soap Substitute Logic: Explain surfactant damage. Standard soap has high pH (alkaline) which disrupts the skin's Acid Mantle (pH 5.5). Emollients preserve this.
- Urea: At low concentration (5%) it hydrates. At high concentration (40%) it is keratolytic (dissolves skin - used for warts/thick heels).
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.