Eosinophilic pustular folliculitis associated with Demodex overgrowth or demodicosis on the face – A report of five cases

Abstract

Eosinophilic pustular folliculitis (EPF) is classified into Ofuji disease, immunosuppression-associated EPF, and infancy-associated EPF. The association of EPF with Demodex infestation is rarely reported. We report five cases of EPF with Demodex overgrowth. All patients were young females presenting with recurrent, itchy papulopustules on the face for 2 months to 2 years. Laboratory tests revealed eosinophilia (n = 2) and iron deficiency anemia (n = 1). Skin biopsy of papulopustular lesions was performed in each patient, and all revealed folliculocentric infiltration with eosinophils. Infundibular pustules containing Demodex mites were found in two patients. All patients had high Demodex densities examined by superficial needle-scraping method (7–18 mites/5 pustules) and/or thumbnail-squeezing method (37–255 mites/cm2). Based on the clinical and laboratory findings, the patients were either first treated as having demodicosis or as having EPF. According to the treatment responses, the cases might represent Demodex-induced EPF or EPF-like reaction (Cases 1–3) or demodicosis superimposed on EPF (Cases 4 and 5). In sum, we report five cases of EPF with Demodex overgrowth (demodicosis). These cases illustrate that the possibility of Demodex overgrowth should be considered in cases of EPF with incomplete treatment response to indomethacin and/or oral corticosteroids. Conversely, EPF should be considered in cases of demodicosis with incomplete responses to antiparasitic treatment.

Keywords

• demodex
• demodicosis
• eosinophilic pustular folliculitis
• superficial needle-scraping method
• thumbnail-squeezing method