The Collaborative International Dictionary of English v.0.48:

Epidermal \Ep`i*der"mal\, a.
   Of or pertaining to the epidermis; epidermic; cuticular.
   [1913 Webster]

WordNet (r) 3.0 (2006):

epidermal
    adj 1: of or relating to a cuticle or cuticula [syn:
           cuticular, epidermal, epidermic, dermal]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "epidermal":
   ankle-deep, cortical, cursory, cutaneous, depthless, dermal,
   dermic, ecderonic, ectodermal, ectodermic, endermatic, endermic,
   epicarpal, epidermic, furry, hypodermal, hypodermic, jejune,
   knee-deep, light, not deep, on the surface, shallow,
   shallow-rooted, shoal, skin-deep, skinny, slight, subcutaneous,
   superficial, surface, testaceous, thin, trivial, unprofound