What are Epidermal Differentiation Disorders (EDDs)?

EDD is a new classification for inherited skin disorders affecting epidermal differentiation. It groups disorders based on the affected gene. This approach aims to pave the way for novel targeted therapies.

  • nEDD (nonsyndromic EDDs): Disorders with primarily widespread cutaneous involvement e.g ichthyoses
  • sEDD (syndromic EDDs): Disorders where there is significant extracutaneous features e.g Netherton's syndrome
  • pEDD (palmoplantar EDDs): Predominantly affecting the palmoplantar surfaces e.g palmoplantar keratodermas (PPKs).

How to build the new names

Diagram illustrating the EDD classification

Why Change the Name?

1

Remove potentially offensive terms

'Ichthyosis' compares a person's skin to fish scales

2

Focus on genetic cause and pathways

TRPV3-pEDD (Olmsted Syndrome); TRPV3 is known to interact with the EGFR pathway, targeting this with erlotinib has shown dramatic results.

3

Improve accuracy of names

'Pachyonychia Congenita' (PC) means thickened nails, but this feature is often not present and the main feature is debilitatingly painful soles.

Source Papers

This database is built upon the articles published in the British Journal of Dermatology:

Overview

Non-syndromic EDD

Syndromic EDD

Palmoplantar EDD