Dandruff/seborrhoeic dermatitis is characterized by an inflammatory genomic signature and possible immune dysfunction: transcriptional analysis of the condition and treatment effects of zinc pyrithione.

Flaking, itching (pruritus) and reddening (erythema) present in seborrheic dermatitis are all tissue level events poorly understood at the molecular level.

This study compared the gene expression profiles of seborrheic dermatitis affected individuals compared to healthy participants. In addition, it also analyzed the effects of zinc pyrithione on these profiles.

Approach

• Scalp biopsies were taken from 16 health participants and from 15 individuals affected by seborrheic dermatitis
• Biopsies were performed both before and after zinc pyrithione treatment
• The RNA (a nucleic acid carrying DNA) was extracted and analyzed from all biopsies

Outcome

• Significant differences in gene expression between healthy skin and lesion sites was revealed
• Areas which showed the most notable differences include:
  • Lipid metabolism
  • Immune response
  • Cell proliferation (cell growth)
  • Apoptosis (cell death)
  • Cell differentiation (process by which less specialized cells become more specialized cells)

Key Points

• Lipid metabolism was documented to be the most strongly affected biological process
• The genes responsible for lipid metabolism (fatty acid, cholesterol and triglyceride synthesis) were strongly down regulated
• Immune response genes involved in defense against pathogens and wounding were strongly up-regulated
• An inverse relationship between genes involved in lipid metabolism ( decreased) and genes involved in immune response (increased) was generally seen at lesion areas
• It appears that lesion affected skin is predisposed at the genetic level
• After 3 weeks treatment with zinc pyrithione containing shampoo gene expression profile showed normalization

Summary

Seborrheic dermatitis affected skin appears to show differences at the genetic level when compared to healthy skin. These genetic differences appear to most notable in areas of fatty acid metabolism and immune response.

Zinc pyrithione containing shampoo was demonstrated to aid in normalizing the difference in gene expression at lesion areas. However, it remains unclear by which method of action this result was achieved (antifungal properties or or non-antifungal properties).

Research Paper Details