Facial demodicosis in the immunosuppressed state: a retrospective case series from a tertiary referral center

Background: Data on Demodex in the immunosuppressed state is limited, focusing mainly on patients with human immunodeficiency virus and hematological malignancies. The aim of this study was to describe the manifestations of facial demodicosis in diverse immunosuppressive states. Methods: The medical records of all patients followed at a Demodex outpatient clinic of a tertiary medical center from January 2008 to November 2020 were retrospectively reviewed. Data on patients who were immunosuppressed while with demodicosis were retrieved. Results: The cohort included 28 patients (17 women and 11 men; median age, 58 years). Types of immunosuppression included treatments with hydroxyurea for polycythemia vera/essential thrombocytosis, mycophenolic acid, tacrolimus, and prednisone for liver and/or kidney transplantation, prednisone with cyclosporine/methotrexate/azathioprine/rituximab mainly for autoimmune diseases, mercaptopurine with/without anti-tumor necrosis factor alpha (TNF-α) for Crohn's disease, chemotherapy for neoplasms, anti-TNF-α for psoriasis, and Cushing's syndrome. The clinical types of demodicosis included: papulopustular, erythematotelangiectatic and fulminant rosacea, hyperpigmented, pityriasis folliculorum, pustular folliculitis, and dermatitis. The diverse clinical presentations led to various differential diagnoses. Topical treatment with ivermectin (monotherapy/combination with other treatments) was effective. Conclusion: Clinicians treating immunosuppressed patients should be familiar with the different forms of demodicosis and include them in the differential diagnosis of facial eruptions.