Herpes Simplex Masquerade Syndrome: Acanthamoeba Necrotizing Stromal Keratitis

Purpose : to report an atypical case of acanthamoeba keratitis.patients & methods : a 19-year-old girl presented with a history of recurrent herpetic keratitis and a history of short-time contact lens wear. laboratory work-up for herpetic, bacterial, and acanthamoeba sources were negative and the patient failied to follow up. on later presentation she had corneal necrotizing stromal ulcer needed penetrating keratoplasty. histological examination revealed acanthamoeba cysts.conclusion : when bacterial cultures are negative other infectious agent should be suspected. if clinical and laboratory work-up confirms the diagnosis of herpetic keratitis but antiviral treatment fails, a possible mixed infection should be looked for. if our work-up is negative, due to lower sensitivity of acanthamoeba culture, acanthamoeba should be suspected and evaluated with proper methods such as polymerase chain reaction