The 100th anniversary of lupus erythematosus tumidus.

In 1909, the term "lupus erythematodes tumidus" was first introduced by the German Dermatologist E. Hoffmann. The next case reports of lupus erythematosus tumidus (LET) were not described until 1930, and in the following years, only a few further cases were reported. This might have been due to the fact that authors have not considered LET as a separate entity different from other variants of cutaneous lupus erythematosus (CLE), and it is likely that skin lesions described under different designations represent the same disease entity. Therefore, LET has been underestimated and neglected in the literature and has been characterized by clinical, histopathological, and immunohistochemical features only in recent years. In particular, phototesting has been crucial in defining LET as a very photosensitive entity of CLE. Up to now, more than 40 reports of LET have been published demonstrating that the course and prognosis of LET are generally more favorable than in other subtypes of CLE. A new classification system, including LET as the intermittent subtype of CLE (ICLE) has been suggested. On the occasion of the 100th anniversary of the first description of LET, we have reviewed the literature and provide here an overview on the different aspects of the disease.