Demodex Abscess: Clinical and Therapeutic Challenges

Abstract

A 52-year-old man suffered from recurrent erythematous papules, plaques, pustules and abscesses over the anterior chest, abdomen and back with severe pruritus for four years. He was under long term systemic steroid treatment for more than 4 years due to arthralgia. Steroid-induced folliculitis or Pityrosporum folliculitis was impressed at first, but treatment with systemic minocyclin and topical benzoyl peroxide for 4 weeks and systemic itraconazole for another 4 weeks showed no improvement. A skin biopsy of an abscess taken from the back revealed a perifollicular infiltration with plasma cells, neutrophils, eosinophils and some foreign body giant cells. Within the sebaceous duct and gland, there were Demodex mites. KOH examinations of the specimens from abscesses revealed many Demodex brevis mites. The skin lesions were unresponsive to topical antiparasitic treatment (benzoyl benzoate and crotamiton). Therefore oral administration of levamisole HCl 50 mg 3 times a day for 10 days was given and all the skin lesions and pruritus were subsided.