A red-eye presentation concerning for vernal keratoconjunctivitis: a case report

Background: Vernal keratoconjunctivitis (VKC) is a chronic, recurrent, and seasonally exacerbated allergic eye disease that can significantly impair quality of life in children. It is a rare disease, with higher prevalence in hot and dry climates. There is a broad differential for a red eye presentation, and the diagnosis of VKC may be complicated when symptoms occur outside typical seasonal patterns or when allergy testing is unclear. We present a case of VKC in Canada, identified on allergy consultation after persistent unresponsiveness to antihistamine treatment. Case presentation: An 11-year-old male presented with a six-month history of bilateral conjunctival redness and swelling, accompanied by seasonal nasal and palatal itch and sneezing. Initial symptoms began atypically in February, later progressing to photophobia and early vision changes. Clinical images showed striking perilimbal Horner-Trantas dots and marked conjunctival inflammation, ecchymosis, and chemosis. Skin prick testing and serum IgE revealed only mild sensitization to cat dander. Multiple topical therapies were trialed; symptoms improved with olopatadine and fully resolved with loteprednol, though attempts to taper the steroid resulted in recurrence. Given clinical features and photographic evidence, VKC was diagnosed, with consideration that persistent environmental cat antigen exposure may have contributed to symptom chronicity. Atopic keratoconjunctivitis and giant papillary conjunctivitis were on the differential but felt to be less likely. The patient was transitioned back to olopatadine to facilitate discontinuation of loteprednol, and was treated with rupatadine for ocular and nasal symptoms. Ophthalmology assessment occurred after he had been off topical steroids for one month, at which time symptoms were minimal and no further suggestions made. Over the following year, he remained stable on daily Pataday and oral rupatadine, ultimately discontinuing antihistamines entirely with only mild intermittent ocular pruritus and conjunctivitis. Repeat skin testing was unremarkable. Conclusions: VKC is uncommon in Canada, but missing it has serious consequences including progressive vision loss. This case highlights VKC in an 11-year-old boy who was repeatedly treated for presumed allergic conjunctivitis despite photophobia and early vision changes. His symptoms presented outside of typical seasonal patterns, with no clear provoking allergen. Successful long-term symptom control was achieved through careful tapering of topical steroids combined with targeted antihistamine therapy. VKC should be considered in cases of conjunctivitis unresponsive to antihistamine therapy, and is important to differentiate from other forms of allergic conjunctivitis to avoid possibly permanent ocular sequelae. A positive skin prick test or serum IgE is not necessary for the diagnosis of VKC. The exact allergen may not be known. Topical and oral antihistamine combination is effective in stabilizing VKC symptoms, with the addition of topical steroids if needed for flares. VKC treatment can require a prolonged course. Referral to ophthalmology for VKC may be considered when vision changes are involved.