Pseudodendritic fungal epithelial keratitis in an extended wear contact lens user.

PURPOSE: Pseudodendritic keratitis in a contact lens wearer is generally associated with acanthamoeba keratitis. We report a case of isolated pseudodendritic fungal epithelial keratitis that occurred in an extended wear contact lens user. METHODS: A 48-year-old woman was evaluated in our clinic for a 36-hour history of left eye pain. She wore extended wear soft contact lenses and frequently rinsed her eyes with tap water. Her left cornea had a paracentral 3-mm area of epithelium with raised ridges in a pseudodendritic pattern. The underlying corneal stroma was normal. A therapeutic and diagnostic corneal scraping of the lesion was performed and sent for Gomori methenamine silver (GMS) staining. The clinical concern was for epithelial acanthamoeba keratitis. RESULTS: The GMS staining revealed septate fungal hyphae within sheets of corneal epithelium. The patient was started on frequent alternating natamycin (5%) and amphotericin B (0.15%) antifungal eyedrops and exhibited a rapid clinical response. Her keratitis completely resolved, and her vision returned to her baseline of 20/25. Corneal fungal cultures showed no growth. CONCLUSIONS: Our case is an extremely unusual presentation of fungal keratitis, which rarely presents as a pseudodendritic epithelial keratitis. There are two previous similar case reports initially misdiagnosed as acanthamoeba keratitis. Clinicians should be aware that isolated fungal epithelial keratitis can present as a distinct entity and should be considered in the differential diagnosis of pseudodendritic keratitis. The GMS staining is an excellent diagnostic test in a patient presenting with pseudodendritic keratitis because it allows rapid diagnosis of acanthamoeba and fungal infections.