Clinical experience treating Paecilomyces lilacinus keratitis in four patients

Abstract

Background: Paecilomyces lilacinus is a saprobic fungus that occasionally causes keratitis in infected patients. Voriconazole, a triazole antifungal agent, is often administered to treat P. lilacinus keratitis, because it is resistant to many antifungal agents. However, some patients may not require voriconazole. Here, we report our experience of treating this infection and compare outcomes between patients treated with or without voriconazole.

Subjects: We retrospectively reviewed four cases of infectious keratitis caused by P. lilacinus and compared treatment course and outcomes among the four cases.

Observations: P. lilacinus was isolated from corneal cultures in all four cases. Three cases developed corneal perforation and underwent keratoplasty. Voriconazole was given in two cases with severe and refractory infection. Both required long-term treatment despite the effectiveness of voriconazole. They also had a medical history of diabetes and corticosteroid therapy. In two cases that were not treated with voriconazole, the eye conditions improved with a short treatment period (2-3 weeks). Neither of these cases had a medical history of diabetes, nor had they used corticosteroids.

Conclusion: Although voriconazole is the most useful antifungal agent for treating P. lilacinus keratitis, this infection can be resolved by other treatments. Voriconazole should be offered to patients with diabetes and/or prior corticosteroid use.

Keywords: Paecilomyces lilacinus; corticosteroids; diabetes; voriconazole.

Figure 1

Case 1. (A) The round, central corneal infiltrate with feathery margins is surrounded by a severely edematous cornea. (B) Enlargement of the infiltrate at 2.5 weeks after discontinuing corticosteroids and starting antifungal agents. (C) Colony of Paecilomyces lilacinus isolated from cornea, and the color of colony in 14 days is lilac on potato dextrose agar. (D) Photomicrograph of P. lilacinus demonstrating the long conidiophores arising from hyphae, tapering phialides, and chains of conidia (lactophenol cotton blue stain). (E) Two weeks after starting treatment with voriconazole, the infiltrate has decreased in size. (F) Two years after the discharge, the cornea is clear and no recurrence of fungal infection has been reported.

Figure 2

Case 2. (A) Nasal scleral hyperemia and nasal peripheral corneal infiltrate with feathery margins. (B) Enlargement of the corneal infiltrate 2 days after discontinuing treatment with corticosteroids and starting antifungal agents. (C) Even though voriconazole decreased the size of the corneal infiltrate, the peripheral cornea is perforated. A fibrous clot was found in the anterior chamber. (D) One year after the discharge, the cornea is clear, and no recurrence of fungal infection has been reported.

Figure 3

Case 3. (A) Perforation of the cornea 1 day after presentation at our hospital. (B) Eight months after surgery, the nasal cornea was clear, and the patient’s visual acuity was 0.8.

Figure 4

Case 4. (A) An upper peripheral corneal infiltrate with feathery margins. (B) Three months after starting treatment with antifungal agents, the cornea was clear, and the patient’s visual acuity was 1.0.