Reticular Erythematous Mucinosis and Lupus Erythematosus Tumidus — Different Diseases or Variations on a Theme?

Both reticular erythematous mucinosis (REM) and lupus erythematosus tumidus (LET) are characterized by erythematous papules and plaques and histopathologically demonstrate a lymphocytic infiltrate with increased mucin. The clinical distinction between these two entities lies in distribution; REM occurs primarily on the chest and back and LET primarily in a photodistributed pattern. REM lesions are papules in a net-like configuration, whereas LET lesions are usually annular plaques. Photosensitivity, rare in REM, is almost always present in LET. Both processes are said to be responsive to antimalarial therapy.

These authors performed two separate studies of REM and LET. In this comparison of the histopathologic features of the two diseases, t…