Ultraviolet association with vernal keratoconjunctivitis with perilimbal pigmentation

Vernal keratoconjunctivitis (VKC) is a chronic bilateral ocular allergic disease affecting mainly children and adolescents. Perilimbal pigmentation (PLP) has been noted as a new sign of VKC in pigmented race of Asian and African origin. To analyze the etiology, clinical significance, and pathophysiology of PLP, and to explore the possible association between ultraviolet (UV) exposure and the presence of PLP in VKC. A PubMed search of articles between January 1983 and January 2024 on VKC with PLP was performed. PLP takes the appearance of spotty pigmentation in the interpalpebral conjunctiva. Activation and proliferation of the melanocytes in the limbus in the status of inflammation had been proposed as possible pathogenesis of PLP. However, the clinical significance of PLP in the process of VKC were still controversial. VKC with PLP were mostly seen in pigmented races in equatorial region with hot, dry climates and strong UV. The regionality of VKC patients with PLP and the interpalpebral distribution of pigmentation suggest possible association of PLP with UV. Elucidating this issue will help to prevent and treat this regional and racial specific VKC.