Keratitis due to Histoplasma capsulatum in Human

Abstract

Purpose: : To report a case of fungal keratitis caused by Histoplasma capsulatum, which to our knowledge is the first reported case in human described all over the world.

Methods: : Case report.

Results: : A 44–year–old male homeless hiker was presented at the Ophthalmology Service – Federal University of Uberlândia (Brazil) on February 06, 2005, for an irritated and painful right eye (OD). He was seen by an ophthalmologist one month earlier and treated for an eye infection with eye–drops that he could not remember the name. He complained that the symptoms had worsen and started with photophobia and yellowish discharge three days before. His ophthalmologic exam showed vision corrected to hand motion OD, presence of abundant thick mucopurulent discharge, conjunctival hyperemia 4+/4+, a stromal grayish type infiltrate with corneal thinning and a widespread epithelial defect. Corneal scrapings were obtained and after that the patient was empirically started on topical moxifloxacin and fortified cefalotin every hour and atropine 3 times daily. The culture grew Serratia marcescens and Streptococcus viridans, resistant to cefalotin. The fortified cefalotin was discontinued and the patient continued with topical moxifloxacin and atropine. The patient presented decrease in his visual acuity to light perception, hypopyon and worse of corneal thinning. He underwent a therapeutic penetrating keratoplasty procedure on February 11, and the corneal button had been sent to anatomopathologic exam. The results of anatomopathologic examination revealed acute fungal keratitis with a great quantity of intra– and extracellular globular structures, morphologically consistent with H. capsulatum. The patient was started on a treatment of topical amphotericin B drops hourly associated with topical moxifloxacin. The cornea presented a persistent epithelial defect and the patient complained of discomfort. On February 24 he underwent to amniotic membrane transplantation. The patient did well postoperatively and the cornea had no signs of infection’s recurrence.

Conclusions: : Although no previously reported worldwide, H. capsulatum can cause infectious keratitis in humans and should be considered in the differential diagnosis of fungal keratitis.

Keywords: keratitis • fungal disease • cornea: stroma and keratocytes