Successful treatment of Paecilomyces lilacinus keratitis in a patient with a history of herpes simplex virus keratitis

Purpose: To report a case of Paecilomyces lilacinus keratitis, initially misdiagnosed as Penicillium sp., in a patient with a longstanding history of herpes simplex virus (HSV) keratitis. Methods: A retrospective case report. Results: A 62-year-old man developed P. lilacinus keratitis. He was treated with topical steroids for immune stromal keratitis secondary to HSV before developing the fungal keratitis. Initial comeal cultures were positive for Penicillium sp., but subsequent cultures identified P. lilacinus to be the causative organism. The patient later developed an anterior chamber abscess. Three penetrating keratoplasties, as well as intravitreal injection of amphothericin B, topical miconazole, subconjunctival miconazole, and systemic fluconazole, were required to eradicate the infection. Conclusion: To our knowledge, this is a first report of P. lilacimis keratitis in a patient with a previous history of HSV keratitis. The causative organism was initially reported as Penicillium sp. on 2 occasions, before the correct diagnosis was made. Paecilomyces keratitis progressed to an anterior chamber abscess in this eye. Aggressive treatment, including a therapeutic penetrating keratoplasty, intravitreal amphothericin B injection, topical miconazole, and systemic fluconazole can be successful in eradicating this extremely difficult-to-treat infection.