Tumid lupus erythematosus (TLE) is a relatively uncommon variant of chronic cutaneous lupus erythematosus. Patients typically present with asymptomatic, edematous, erythematous papules and plaques with no surface changes, most commonly on the trunk, face, and neck. Photosensitivity is a hallmark feature: lesions are often brought about by ultraviolet (UV) light exposure. However, TLE lesions may also present on skin not exposed to the sun. TLE shares many features with reticular erythematous mucinosis (REM), to the extent that many authorities consider them to be related entities. However, lesions of REM tend to have a reticular appearance, which differentiates this entity from TLE.

In general, TLE is a skin-limited condition. It is characterized histologically by a lymphocytic infiltrate of T-cells with a CD4:CD8 ratio of roughly 4:1, differentiating this from other clinical mimickers with predominant CD8 infiltration such as pseudolymphoma. Koebner phenomenon (isomorphic response) and relapses at sites of trauma have been reported.

Antinuclear antibody (ANA) positivity occurs in a very small subset of patients, and 10% of patients with systemic lupus erythematosus (SLE) will have lesions consistent with TLE. In addition, there have been a few reports of patients with TLE occurring with discoid lupus erythematosus. Females seem to be affected more frequently than males. The youngest reported patient to date was 16 years old.