Demodex folliculorum is a commensal mite that inhabits the orifices of cutaneous pilosebaceous follicles. Overgrowth of these organisms can lead to Demodex folliculitis, which typically presents as papules and pustules predominantly involving the temples, cheeks, and occasionally the chest. We present a 51-year-old woman with iatrogenic Demodex folliculitis secondary to immunosuppressive treatment for an autoimmune connective tissue disease. Histopathological exam of a skin biopsy, which revealed follicular Demodex mites, confirmed the diagnosis. The eruption was treated with oral ivermectin and topical metronidazole gel, and the patient's immunosuppressive regimen was decreased, resulting in marked improvement in the eruption within 6 weeks and no worsening of her underlying autoimmune disorder. This case emphasizes the importance of considering Demodex folliculitis in the differential diagnosis of a new onset rash in the context of immunosuppressive treatment.
Keywords: Demodex; cutaneous autoimmune disease; folliculitis; immunosuppression; rash.
© 2023 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.