Pachyderma: what does it mean ?

• The Greek words of origin are:
  • παχυς= pachus = thick
  • δερμα = derma = skin

• “Pachyderm” refers to a family of mammals with thickened skin and includes the elephant, hippopotamus and rhinoceros.
• “Pachys” is frequently used in medical terminology: a lot of human organs can thicken: skull, meninges, spine, lungs, heart, peritoneum…

• In dermatology the terms pachderma (thick skin) and pachyonychia (thick nails).
• Well known but very rare is pachyderma verticis gyrata; it is the former term of cutis verticis gyrata. This congenital or acquired condition presents as thickened folds in the scalp. A few syndromes can be associated with this type of pachyderma such as pachydermoperiostosis of Touraine-Solente-Golé. In this syndrome, the thickening not only concerns the scalp, but can also thicken the arms, legs and face. Because of the hyperostosis, the hands and toeneails appear prominent (and “look fat”).
• Elephantiasis nostras verrucosa = thickened cobblestoned papules occuring in chronic lympoedema. General thickening of the skin (pachyderma) also occurs.

Contributors

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

Source of information: Harms M. Dermatologica Helvetica (The Swiss Journal of Dermatology and Venereology: www.dermatologicahelvetica.com