Reticular erythematous mucinosis: a review of patients' characteristics, associated conditions, therapy and outcome in 25 cases.

Background: Reticular erythematous mucinosis (REM) is an uncommon disease, the nosology and specific characteristics of which are controversial because most reports deal with single cases or small series.

Objectives: To describe the characteristics of patients with REM regarding demographics, clinical and pathological features, comorbidities, treatment and course.

Methods: A retrospective and prospective study was conducted on 25 patients diagnosed with REM in the setting of university-affiliated dermatology departments and dermatopathology centres.

Results: Of the 25 patients with REM, 16 were women (sex ratio 2 : 1) and the mean age was 46 years. The roles of sun exposure and oral contraceptives were ambiguous. Associated diseases included hypertension (n = 4), malignancies (n = 3), autoimmune diseases (n = 3) and Borrelia infection (n = 1). Immunological studies (including serology and direct immunofluorescence) were noncontributory. The response to antimalarial treatment was good in > 80% of cases. Worsening or recurrence of the lesion after treatment discontinuation, or in the course of the disease, occurred in 31% of patients.

Conclusions: We present the largest REM case series to date. The reticular pattern with involvement of the midline of the chest and back, the predilection for middle-aged women, the controversial relationship with photosensitivity and the possible association with other conditions such as malignancies and thyroid dysfunctions are the main characteristics that makes REM a recognizable disease.