Topical steroids are the main treatment for a range of inflammatory skin conditions including psoriasis and atopic dermatitis. In a previous blog I reviewed the evidence of their safety in the long-term treatment which showed evidence of their effectiveness and limited evidence of harm. In order to minimise any potential risk of side effects when used in the long term, the adjunct use of emollients has been promoted [1].
The Steroid Sparing Effect
The steroid sparing effect of using an emollient has been recognised [2]. The use of topical steroids alongside any topical steroid therapy has shown that when used together, the amount of topical steroid used to produce clinical improvement in atopic dermatitis is significantly reduced. This has been described as the “steroid sparing” effect of emollients. The mechanism is not clearly understood. However, it has been suggested that emollients may limit the penetration of irritants and allergens into the skin that may trigger inflammation. Moreover, specific ingredients in emollient preparations are known to have anti-inflammatory effects [3].
On this basis, it has long been advised that the concurrent use of emollients, whilst using topical steroids, is good practice and advisable to patients using topical steroids for skin conditions. However, there is little guidance on how this is best achieved. That is, which should be applied first and what time gap should be used between their applications? Simultaneous application of the two products on the skin is not recommended as it may affect drug delivery into the skin although this has not been thoroughly investigated [4]. Advice given to date from various UK dermatological sources suggests the following (correct as of 16/12/2023):
1. Allergy UK
Emollient first. 15-30 minutes, then a topical steroid
2. Clinical Knowledge Summaries (Topical Steroids)
No order preference 20-30 minutes between the two products application on the skin.
3. British Association of Dermatologists Information Leaflet
No preference of order, no advice on time period.
Topical steroid first, 30 minute gap, emollient afterwards.
Emollient first with a variable time gap depending on the emollient then the steroid.
The latter resource from the BDNG acknowledges here is a lack of evidence for guiding these recommendations and is recommended on expert opinion.
Latest research on emollient and topical steroid application regimes
Recently, there have been two papers published by the same research team which have investigated skin permeation and penetration of two steroid products in the presence of emollient using a skin explant model. Researchers at the University of Hertfordshire, in two separate papers, selected two commonly prescribed topical steroids - mometasone furoate and clobetasol propionate and looked at their 24 hour absorption profiles when emollients were applied to the skin (before or after steroid application) at either 5 or 30 minutes apart or with steroid alone[4, 5].
The results from the two studies were strikingly similar. Significantly reduced topical steroid delivery to the skin was seen when it was applied before or after common emollient products compared to just applying the topical steroid alone.
However, if the topical steroid was applied first before an emollient, the reduction in steroid delivery to the skin was less than if the emollient was applied first. The explanation from the authors was that the emollient application formed an additional barrier affecting topical steroid delivery.
Implications for practice
The results here suggest that the application regime for emollients and steroids may need to be revised. The study was laboratory based, using scrotal skin as the model. This may be needed to be tested in a more real-life situation to asses the true effect in practice, although such measurements, in vivo are technically more challenging.
One recommendation from this work for consideration is that emollients could be applied at at different time of day completely. That is, steroids in the morning then emollients in the evening, for example, leaving a longer time gap for complete absorption. A comparative clinical study examining this regime with the 30-minute time gap between applications may yield observable differences to inform practice.
For the moment, it is still evidence from existing research that the two preparations compliment each other and may reduce the unwanted side effects of topical steroids but the timing between applications may need to be tweaked - particularly as most organisations currently recommend an emollient first.
References
1. Harcharik, S. and J. Emer, Steroid-sparing properties of emollients in dermatology. Skin Therapy Lett, 2014. 19(1): p. 5-10.
2. Grimalt, R., V. Mengeaud, and F. Cambazard, The steroid-sparing effect of an emollient therapy in infants with atopic dermatitis: a randomized controlled study. Dermatology, 2007. 214(1): p. 61-7.
3. Moncrieff, G., et al., Use of emollients in dry-skin conditions: consensus statement. Clin Exp Dermatol, 2013. 38(3): p. 231-8.
4. Beebeejaun, M.T., et al., Reduced skin permeation and penetration of clobetasol propionate when Dermovate cream is applied at short time intervals with emollients. JEADV Clinical Practice, 2023. 2(4): p. 718-726.
5. Beebeejaun, M.T., et al., Skin permeation and penetration of mometasone furoate in the presence of emollients: An ex vivo evaluation of clinical application protocols. Skin Health Dis, 2023. 3(3): p. e215.