Pediatric phlyctenular keratoconjunctivitis and its spectrum of disease: An updated review

Pediatric phlyctenular keratoconjunctivitis (PKC) is a common nodular inflammatory disorder characterized by the presence of phlyctenules, which are raised yellow-gray lesions on the conjunctiva or cornea. As an entity on the spectrum of disease of pediatric blepharokeratoconjunctivitis, PKC involves a dysregulated immune response focused on a type IV hypersensitivity reaction. PKC classically has an antigenic trigger from an infectious microbe and is frequently co-morbid with conditions such as rosacea, demodicosis, and blepharitis. Clinically, patients present with ocular irritation, and examination findings include both corneal and conjunctival pathology with the presence of phlyctenules. Complications can arise, including corneal scarring, neovascularization, ulceration, and even perforation. The management of PKC involves the treatment of underlying blepharitis, as well as inflammation control with anti-inflammatory antibiotics and topical steroids or topical immunomodulatory agents, such as cyclosporine A. Patients with ulceration may require topical antibiotics, while patients with perforation may require surgical intervention. PKC is a major cause of referrals to pediatric cornea specialists and has the ability to cause significant visual morbidity. Thus, early recognition and appropriate management of this condition are critical to prevent permanent visual impairment in the vulnerable pediatric population.