Applying a moisturizing cream containing propylene glycol after applying topical hydrocortisone to the skin of patients with atopic dermatitis was shown to increase absorption of the glucocorticoid.

Original article:  Turpeinen,M.   Absorption of hydrocortisone from the skin reservoir in atopic dermatitis. British Journal of Dermatology. 1991; 124:358-360.

Reviewed by Allene Fonseca, PGY-3 Internal Medicine Resident Loma Linda University.

• Turpeinen reported on the absorption rates of topical hydrocortisone applied to the skin of 7 patients (aged 4 months to 39 years) who were hospitalized for atopic dermatitis (AD) exacerbation.
  • Topical glucocorticoids were discontinued in all patients 36 hours prior to taking the absorption test.
  • A dexamethasone test was used to suppress morning cortisol secretion.
    • Dexamethasone is a strong steroid, 30-40x more potent than cortisol.
    • Administration of dexamethasone provokes (the body to have) a counter response of making less cortisol, because the homeostasis response sensed adequate corticoid in the system.
  • The serum level of cortisol of the 7 patients was checked after dexamethasone was given to suppress their natural cortisol production.
  • The dexamethasone suppression test was successful because all of the patients had below normal levels of plasma cortisol in the morning, compared to pre-treatment levels which were within normal limits.
    • To provide adequate suppression, the dexamethasone dose was adjusted to compensate for the percentage body surface area that had been receiving topical glucocorticoids previously.
      • For example, 0.25mg of dexamethasone was given for a body surface area of <0.5meters squared, and 2mg was given for a body surface area of >1.5 meters squared.
    • There were no noted side-effects of dexamethasone.
    • Subsequently, glucocorticoid absorption was determined by measuring serum cortisol levels, at set time intervals, beginning in the morning at 8:00-9:00, and subsequently 2h, 4h, 12h, 14h, 16h, and 24 h after the application of 1% hydrocortisone cream. In addition, the 3 adults’ serum was also checked again at 26 and 28 hours.
      • The cream was applied to the exact same areas that the topical hydrocortisone was applied too.
      • Children used 33-59g of topical hydrocortisone, and adults used 50-75g.
    • A moisturizing cream containing 80% water and 5% propylene glycol was applied to the hydrocortisone application sites, following the 12 hour blood sample.
    • In the adults, the moisturizing cream was again applied after the 24 hour blood sample was collected.
      • The changes in cortisol level between the different time intervals were statistically significant.
      • After applying 1% hydrocortisone once, plasma cortisol rose within 4 hours, and then steadily lowered.
    • In the 8 month old and the 3, 7 and 39 year old patients there was a rise in cortisol levels just 4 hours after applying the moisturizing cream, suggesting that within 4 hours the moisturizing cream can support increased absorption of topical steroid from skin reservoirs in some individuals.
    • In the 4 month old and the 19 and 20 year old patients there was not a significant rise in cortisol levels after applying the moisturizing cream
    • Following the 24 hour blood draw, the 3 adults again applied moisturizer.  There was no significant rise in serum cortisol levels. This finding suggests that applying moisturizer 24 hours after applying topical steroids does not increase the absorption of steroids.
  • This study suggests that topical hydrocortisone may be retained in the skin of patients with AD for up to 12 hours, and the absorption from the skin may be further enhanced by applying a moisturizing cream containing water and propylene glycol (PG).
    • PG, may work synergistically to increase the absorption of hydrocortisone (1).

References

1. Turpeinen, M.   Absorption of hydrocortisone from the skin reservoir in atopic dermatitis. British Journal of Dermatology. 1991; 124:358-360.
2. Zesch A. Schaeffer H. Penetration of radioactive hydrocortisone in human skin from various ointment bases. II. In vivo experiments. Arch Dermatol Forsch1975: 252: 245-56.