Pachyderma is the thickening of skin like that of a pachyderm. It occurs in the condition Pachydermoperiostosis; an X-linked genetic disorder. ... Found on http://en.wikipedia.org/wiki/Pachyderma
Pachyderma: Thick skin, like that of a pachyderm (an elephant, rhinoceros, or hippopotamus). From the Greek pachydermos meaning 'thick skin' from pachys meaning 'thick' + derma meaning 'skin.' The adjective is pachydermatous. Found on http://www.medterms.com/script/main/art.asp?articlekey=32876