ALTERNARIA ALTERNATA KERATITIS – A CASE REPORT

Alternaria spp are ubiquitous pigmented filamentous fungi that can cause opportunistic human infections and can be found in skin infections, ocular mycosis and rhinosinusitis. The purpose of this case was to report a case of Alternaria alternata keratitis after ocular trauma with biological material with good clinical and functional evolution after topical therapy with voriconazole.

Corneal Section of Ophthalmology Department of Centro Hospitalar Universitário do Porto, Porto, Portugal.

A 44-year-old man was attended on emergency room for acute onset ocular pain and photophobia in his right eye (RE), secondary to an eye trauma with a tree branch, 3 days before. Patient had previous history of type 1 diabetes mellitus, diagnosed 24 years before, and history of reno-pancreatic transplant, 5 years before. RE best corrected visual acuity (BCVA) was 20/80; left eye BCVA was hand motion (secondary to a diabetic neovascular glaucoma). Slit-lamp examination revealed a temporal corneal epithelium erosion and a peripheral anterior stromal infiltrate with 2x1.5mm. Patient started topical treatment with clotrimazole, moxifloxacin, bromofenac and cyclopentolate. After 15 days of treatment (D15), there was a progressive deterioration of symptoms: slit lamp examination revealed a paracentral corneal ulcer with an associated stromal infiltrate measuring 4.7mmx2.7mm. Corneal samples were collected and inoculated in blood and chocolate agars, in liquid Tyoglicolate and in Sabouraud selective fungal medium. Topical therapy was changed to fortified vancomycin, fortified ceftazidime and fortified voriconazole. On D25, microbiological study revealed a pigmented filamentous fungus identified as Alternaria alternata by microscopic morphology and by mass spectrometry (system VITEK® MS). Therapy was adjusted to topical moxifloxacin and fortified voriconazole during approximately 4 months. Six months after the clinical onset, BCVA progressively improved to 20/25 with only a paracentral leukoma at slit-lamp observation.

This case report describes a mycotic keratitis caused by Alternaria alternata after corneal trauma with biological material. Despite diagnostic and therapeutic difficulties, the patient had a good evolution after therapy with voriconazole. Microbiological study was determinant for correctly targeting the treatment. This case enhances the importance of considering alternative etiological diagnoses in infectious keratitis refractory to the conventional therapy, especially when history of trauma with biological material is known.