Does tachyphylaxis occur in long-term management of scalp seborrheic dermatitis with pyrithione zinc-based treatments?

Abstract

BACKGROUND:

Scalp seborrheic dermatitis and dandruff (SD/D) are chronic conditions requiring long-term treatment. There is a common belief that patients frequently experience decreasing benefits over time when using a single product. This physiologic accommodation is termed tachyphylaxis.

AIM:

To systematically investigate the anecdotal belief that tachyphylaxis occurs in long-term treatment of SD/D using quantitative clinical assessments.

METHODS:

An international questionnaire completed by 722 dermatologists assessed the belief of tachyphylaxis incidence with pyrithione zinc (PTZ)-based shampoos, time course, occurrence relative to active ingredients, and effect of switching products. Two double-blind, randomized, clinical evaluations were conducted, 24- and 48-week studies, whereby a 1% PTZ shampoo, a 2% PTZ shampoo, or a matched placebo control shampoo was used by each subject for the duration of the study. Dermatologists assessed the adherent scalp flaking (scale of 0-10) at baseline and at specified intervals.

RESULTS:

Sixty-four per cent of responding dermatologists believed tachyphylaxis occurred with PTZ products, and most felt that tachyphylaxis occurred within 3 months of use. Evaluation of mean treatment responses vs. placebo and individual responses as a function of study duration showed a consistent benefit for all products at all time points; therefore, no evidence for tachyphylaxis was found (within 48 weeks of treatment).

CONCLUSION:

No evidence for tachyphylaxis in SD/D treatment by PTZ-based shampoos was found. Compliance could explain the decreasing response rate seen over time; the solution is to choose an affordable therapeutic product that is effective long term without cosmetic trade-offs.

• Authors: James R Schwartz, Heather Rocchetta, Pravit Asawanonda, Fangyi Luo, Jennifer H Thomas
• Journal: International journal of dermatology (Int J Dermatol) Vol. 48 Issue 1 Pg. 79-85 (Jan 2009) ISSN: 1365-4632 [Electronic] England
• PMID: 19126058 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Hair Preparations
• Organometallic Compounds
• Pyridines
• pyrithione zinc

Topics

• Administration, Topical
• Dermatitis, Seborrheic (diagnosis, drug therapy)
• Dermatology
• Female
• Hair Preparations (adverse effects)
• Humans
• Incidence
• Long-Term Care
• Male
• Multicenter Studies as Topic
• Organometallic Compounds (adverse effects, therapeutic use)
• Pyridines (adverse effects, therapeutic use)
• Risk Assessment
• Scalp Dermatoses (diagnosis, drug therapy)
• Sensitivity and Specificity
• Surveys and Questionnaires
• Tachyphylaxis
• Time Factors