Reticular erythematous mucinosis occurring in a brother and sister

Reticular erythematous mucinosis (REM) is a rare, primary cutaneous mucinosis clinically characterized by a persistent reticular erythema on the mid chest and mid-upper back, and histologically by a mononuclear cell infiltrate and deposits of mucin in the dermis. To our knowledge, the present report of REM occurring in a Caucasian man and his sister is the first reported case of familial REM. Since a host-specific immune response to unknown antigens may be involved in the pathogenesis of this entity, human leukocyte antigen typing was determined and compared to those reported in autoimmune diseases.