Lichenoid dermatitides. A proposal of classification for an "unidentified" subset

A. V. Marzano, M. Caproni, M. Vanotti, P. Fabbri

Research output: Contribution to journalArticlepeer-review


Aim. Lichenoid dermatitides (LD) represent a group of disorders resembling idiopathic lichen planus (LP) clinically and histologically, but usually having various causes, most notably drugs, chemicals and viruses, as factors inducing the lichenoid tissue reaction. Based on our case series and a review of the literature, and in order to define a single nomenclature for this heterogeneous subset, we propose a classification primarily taking into account aethiologic aspects and clinical features. Methods. The latter comprises, other than well-recognized variants such as lichenoid drug eruptions, lichenoid contact dermatitis and lichenoid graft-versus-host disease, a distinct entity such as keratosis lichenoides chronica, overlap patterns between LP and lupus erythematosus, the recently reported LD in paraneoplastic pemphigus, the so-called solitary lichenoid benign keratosis and a provisional virus-induced LD. Results. The common clinical findings are characterized by localized or generalized "lichenoid" papules, which are usually larger and more psoriasiform than lesions of LP, usually lack Wickham's striae and show a greater tendency toward residual hyperpigmentation. Eczematous or eczematide-like manifestations may coexist and alopecia can not rarely occur. The extremities are the most commonly involved sites, whereas sites of predilection of LP as well as oral or genital mucous membranes and nails are spared. Moreover, some histopathological features, including focal parakeratosis, focal interruption of the granular layer, cytoid bodies in the upper layers of the epidermis, presence of eosinophils and plasma cells, are more characteristic of LD. Conclusions. In conclusion, we suggest that the expression "lichenoid dermatitis" serves to define disorders belonging to a distinctive group and not merely "unidentified" lichenoid patters other than LP.

Original languageEnglish
Pages (from-to)303-315
Number of pages13
JournalGiornale Italiano di Dermatologia e Venereologia
Issue number4
Publication statusPublished - 2006


  • Keratosis
  • Lichen planus
  • Lichenoid dermatitis
  • Lichenoid drug eruption
  • Lichenoid graft versus host disease
  • Lichenoides chronica
  • Solitary lichenoid benign keratosis

ASJC Scopus subject areas

  • Dermatology


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