Ophthalmologists should look past the eyes in patients presenting with a persistent ocular allergic response and be mindful that sight-threatening vernal keratoconjunctivitis is a possibility.
Reviewed by Dr Leonard Bielory.
Vernal keratoconjunctivitis (VKC) is a progressive, vision-threatening condition. However, it is rare and may not be in the forefront of clinicians’ minds when evaluating a child with a persistent allergic ocular surface complaint. In fact, 88% of clinicians in one study noted that primary care physicians and paediatricians commonly under-diagnose or misdiagnose the disorder—which then goes untreated or undertreated—largely because the later involvement of the cornea can be misleading.
This finding was reported by Dr Leonard Bielory, a professor of medicine, allergy, immunology, and ophthalmology at Hackensack Meridian School of Medicine in Nutley, New Jersey, United States. The limited awareness of VKC is the focus for Dr Bielory, who emphasised it as a barrier to timely identification and management of this disruptive ocular surface disorder. Frequently, VKC is initially misidentified as an allergy or infection, and referral to a specialist is often delayed until symptoms have become severe.
VKC begins in the warmest months worldwide. This characteristic can lead clinicians to confuse it with springtime (or “vernal”) allergic conjunctivitis. The corneal inflammatory component, however, emerges later and is recurring. As Dr Bielory stated, “The condition is thought to mislead clinicians into thinking it is just a seasonal problem [but it] may also have a perennial component that develops with time.”
The key factor, Dr Bielory said, is that VKC should be considered in children who present with a persistent ocular allergic complaint, which may be the more pronounced type of conjunctivitis that can affect the cornea. A clue to diagnosis may emerge when parents report using over-the-counter (OTC) ocular treatments to no avail. “This should be the trigger to additional, more thoughtful involvement by their clinicians, such as referral to allergy specialists and ophthalmologists,” he advised.
The following timeline may be helpful, Dr Bielory explained. During the patient’s first season with an ocular reaction, vernal conjunctivitis and seasonal conjunctivitis may have similar presentations. During the second season of the allergic response, however, the vernal component (associated with warmth and different regional pollinating seasons) begins to progress more than the seasonal component, which remains seasonal.
Then, possibly during the second and third seasons, a great degree of progression may be seen during the year of sensitisation, bearing in mind that there are individual degrees of progression among patients. The patient then moves into the clinical phase.
Dr Bielory explained that a confounding factor in the diagnosis of VKC is how allergies develop (i.e., over time) in infants and young children. Immunoglobulin G antibodies inherited from the mothers protect babies for about 6 months. Immunoglobulin E, the allergy antibody, requires exposure to an offending agent over time, followed by development of the immune response against that agent.
Allergies may begin to manifest in babies 6–9 months after birth. Allergies exhibit nasal and ocular symptoms (rhinoconjunctivitis) in almost equal proportions, as physicians should know.
During the second year for children with developing VKC, symptoms worsen and become more unresponsive to treatment. An allergy work-up is needed, but, Dr Bielory stated, when ocular corticosteroids are prescribed and the patient does not improve, clinicians should suspect something more than seasonal allergic conjunctivitis (i.e., the vernal component).
Minor VKC symptoms include photophobia, tearing, burning and pruritus, with minimal impact on a patient’s quality of life. This scenario is often misdiagnosed as pink eye or allergic conjunctivitis.
Moderate VKC symptoms include photophobia, pruritus and discharge of mucus, with moderate sizes and numbers of cobblestone papillae in the upper tarsal conjunctiva or around the edge of the cornea (limbal form of VKC). Patient quality of life is moderately affected.
Severe symptoms of photophobia, pruritus and discharge of mucus, are accompanied by large cobblestone papillae, punctate epithelial erosions and Horner-Trantas dots. Quality of life is substantially affected, and the disease can potentially threaten vision if left untreated as it starts to affect the visual axis of the cornea.
As mentioned, OTC ocular treatments will not work. Use of oral antihistamines may cause increased ocular dryness over and above the abnormal tear film development in the vernal component.
“With antihistamines, there begins to be an increase in tear film dysfunction that comes with the allergy affecting the ocular surface,” Dr Bielory said. “However, in VKC, over-production of tears in response to corneal irritation usually leads to practitioners increasing the use of antihistamines, compounding the ocular surface issue,” he added.
Nevertheless, within this less-than-clear clinical picture, several treatments can be called into play. Treatment of the ocular surface progresses from lubricants to ophthalmic antihistamines to corticosteroids. Dr Bielory uses the steroid burst treatments over 1–2 weeks to avoid increases in intraocular pressure.
He advised that physicians should be aware of the chronic inflammation that induces the activity of certain cell types that will lead to corneal involvement. At this point, Dr Bielory explained, steroid-sparing treatments should be introduced, such as ciclosporin, which decreases the overall immune response of IL-2 and the cytokines.
Ciclosporin ophthalmic emulsion 0.1% (Verkazia,Santen), a steroid-sparing drug, is the first and only topical immunomodulator approved by the United States Food and Drug Administration for treating adults and children with VKC. In addition, Sinusol Breathe Easy (DRBRX), a non-steroidal OTC product, works by clearing nasal mucus and decongestion, which also benefits the ocular symptoms associated with allergies.