Lichen: from the botanical garden to dermatology

• The greek word from which this term comes from is :

  λειχην = leichen = lichen (dartrous)

• This denomination was given following botanics, to describe dermatoses defined by a gathering of papules or elevated lesions (plaques) which resemble lichen (or dartrous-like)
• On the famous tree of dermatoses by Alibert in 1828, dartrous (lichen-like) dermatosis figure on the 4th branch to the left in continuation of eczematous, exanthematous and “teigneuses” (tinea-like but that is inapprorpiate as Alibert did not know the skin lesions were linked to a fungal infection)

• Today, this term (lichen) is used for skin conditions were papules are regrouped. Examples include lichen planus, lichen striatus, lichen nitidus…

Contributors

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

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