Erythroderma: A Retrospective Study From a Single Institution.

Erythroderma is a severe, chronic condition that can affect more than 90% of the body surface area, occurring either idiopathically or secondarily to various underlying diseases. There have been several reports of erythroderma from outside Japan, while reports from inside Japan are limited. In this study, we retrospectively reviewed the clinical characteristics, underlying diseases, and treatments of patients diagnosed with erythroderma at our department between 2008 and 2024. A total of 147 patients were identified (122 males, 25 females; mean age, 69.2 years). Idiopathic erythroderma was the most common etiology (n = 50, 34.0%), followed by chronic eczema (n = 30, 20.4%), psoriasis (n = 22, 15.0%), drug eruptions (n = 19, 12.9%), malignancies (n = 14, 9.5%), and bullous diseases (n = 9, 6.1%). Malignancies included both hematologic malignancies (n = 3, 2.0%) and solid cancers (n = 11, 7.5%). Serum levels of thymus and activation-regulated chemokine (TARC) and IL-25 were significantly elevated in patients with erythroderma, supporting the notion that erythroderma favors Th2-dominant conditions. In addition, erythroderma can occur in association with malignancies. Cases without underlying inflammatory conditions should be screened for internal malignancies, and even if none are detected, careful follow-up is necessary.