Acanthamoeba keratitis classically presents with pain disproportionate to clinical signs and a ring infiltrate. Which stage must be distinguished clinically because it mimics herpetic stromal keratitis?

• A The ring infiltrate stage with stromal involvement
• B The late perineural infiltrate stage
• C The ulcer formation stage with hypopyon
• D The early pseudodendrite (dendritiform epithelial) stage ✓

Explanation

Early Acanthamoeba keratitis can produce pseudodendrites — irregular epithelial lesions that closely resemble the true dendrites of HSV keratitis, leading to misdiagnosis and treatment with steroids/antivirals that worsen Acanthamoeba infection. True HSV dendrites have terminal bulbs and stain with rose bengal at their margins, while Acanthamoeba pseudodendrites lack terminal bulbs and are more irregular, raised, and non-fluorescein-staining at margins. History of contact lens wear in river/tap water exposure aids differentiation.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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