High-Yield Overview: Vernal Keratoconjunctivitis (VKC)

This type of article, "High-Yield Overview," aims to briefly summarize the key points of a disease or concept with little explanation.  Because there will be other articles that will go into greater detail about these conditions, this will hopefully serve as a quick review of the topic.  All of the emphases are mine as little ways to help me remember details I thought were important to know.  While I am terming these articles as high-yield, any highlights that are similar to actual OKAP or board exam questions are coincidental and should be taken to mean that you really need to know that material.

Pathogenesis

  • Type I & IV hypersensitivity

Epidemiology

  • Predominantly male children (2:1 in children, evens out in adulthood)
  • Most common cause of ophthalmic morbidity among Palestinians in West Bank/Gaza Strip
  • Limbal VKC:  African or Asian descent (regardless of location)
  • 50% have a family history of allergic disorders
  • Associated with a history of atopic disease (most commonly asthma, 1/3 have multiple diseases), keratoconus (15%)

Histopathology

  • Conjunctival infiltration of eosinophils (90%), lymphocytes, plasma cells, monocytes

Clinical presentation

  • Typically presents during Spring (hence the name vernal)
  • Bilateral (98%) inflammation of cornea & conjunctiva (year round in tropical environments)
  • Itching, blepharospasm, photophobia, blurred vision, mucoid discharge, filaments (part of DDx for filament keratopathy)

Palpebral VKC

  • Upper > lower palpebral diffuse papillary hypertrophy, bulbar conjunctival hyperemia/chemosis
  • Giant papillary conjunctivitis:  “cobblestone” in appearance (part of DDx for GPC)

Limbal VKC

  • Atopy less common than in palpebral VKC
  • Thickened, gelatinous limbal papillae w/↑ perilimbal conjunctival pigmentation
  • Superior pannus:  can occasionally have 360° corneal neovascularization
  • Horner-Trantas dots:  whitish dots of aggregated degenerated eosinophils + epithelial cells
  • Shield ulcer:  noninfectious epithelial ulcers with underlying stromal opacification

Clinical course

  • Recurrent but typically burns out in puberty

Treatment

Mild

  • Climate modifications, antihistamines, mast-cell stabilizers (start 2 weeks prior to “season”)

Severe

  • Topical steroids (pulse therapy):  Q 2 hrs x 5-7 days with rapid taper; prednisolone particles stick between papillae (consider using something soluble like dexamethasone phosphate instead)
  • Supratarsal subconjunctival steroid injection (for compliance):  located superior to upper border of superior tarsus (free from subepithelial adhesions)
    • 0.5-1.0 mL of short-acting dexamethasone (4 mg/mL), long-acting triamcinolone (40 mg/mL)
  • Topical cyclosporine (2% needed, not Restasis dosages):  2-4x/day
    • Side effects:  punctate epithelial keratopathy, ocular surface irritation

References