Demodicosis is caused by Demodex
mite infestation and can present with a variety of clinical manifestations, including
pityriasis folliculorum type,
rosacea-like type,
folliculitis-like type and
perioral dermatitis-like type. Therefore, this skin condition is often misdiagnosed or underdiagnosed. This report presents a 19-year-old woman with a history of
pityriasis folliculorum type demodicosis and successful treatment with oral
ivermectin. After one year of remission, the patient began to develop a dry, itchy
rash on her face for one month before multiple small edematous papules and pustules gradually appeared on both cheeks. The patient was first diagnosed as
acne vulgaris and treated with
doxycycline for 2 weeks, but the clinical symptoms did not show any signs of improvement. After reassessment based on clinical presentation and laboratory examination that found multiple Demodex mites from pustules and
rash on both cheeks, the patient was diagnosed with
folliculitis-like type demodicosis. However, this patient still had a very good response to oral
ivermectin and
metronidazole gel, and all clinical symptoms disappeared within 4 weeks
after treatment. This is a case report of demodicosis imitating
acne vulgaris and the first report demonstrating a change in clinical manifestations of demodicosis from
pityriasis folliculorum type to
folliculitis-like type.