Expanding the Interface: Overlooked Dermatologic Disorders With Ocular Involvement

The interface between dermatology and ophthalmology offers a rich arena of overlapping clinical entities. The recently published review by Rathore et al. [1] has comprehensively catalogued numerous conditions; however, several additional genetic, metabolic, and autoimmune disorders also merit inclusion due to their diagnostic value and systemic implications. Given the innumerable conditions that affect the eyelashes, eyebrows, and eyelids, this letter focuses solely on disorders that involve both the skin and the eye proper, excluding those limited to adnexal involvement. Furthermore, only conditions omitted by Rathore et al. are discussed here, to augment their existing review. Blistering diseases, both inherited and autoimmune, deserve specific attention for their ocular consequences. In epidermolysis bullosa (EB) (especially junctional and dystrophic subtypes), mucocutaneous fragility may result in keratoconjunctivitis, cicatrisation, symblepharon formation, keratitis, corneal erosions/ulcer, perforation and scarring. Retinal detachment has been reported in junctional EB [2]. Autoimmune subepidermal blistering diseases such as ocular mucous membrane pemphigoid (MMP) exhibit ocular involvement in approximately 61%–70% cases, typically presenting with conjunctival fibrosis, forniceal shortening, and progressive cicatrisation culminating in blindness if untreated. Though less common, pemphigus vulgaris, an intraepidermal blistering disorder, can involve the conjunctiva in 7%–26% of cases, often presenting as bilateral conjunctivitis with conjunctival hyperaemia. Paraneoplastic pemphigus demonstrates ocular manifestations in 41%–70%, frequently as bilateral cicatrizing conjunctivitis, symblepharon, and fornix foreshortening [3]. Autosomal recessive congenital ichthyoses (ARCIs), including lamellar ichthyosis, congenital ichthyosiform erythroderma, and harlequin ichthyosis, often manifest with cicatricial ectropion due to cutaneous tautness. This predisposes to exposure keratitis and even corneal scarring in infancy. Comma like deep stromal punctate corneal opacities have been reported in 50% cases of X-linked recessive ichthyosis. Rarely, Salzmann nodule on the cornea has been linked to ichthyosis vulgaris. Besides the group of syndromic ichthyoses, several metabolic disorders and photosensitive genodermatoses with ocular manifestations were not addressed by Rathore et al. and are summarised in Table 1 [4-7]. AR; most common mutation in the PHYH gene and less commonly PEX7 mutation leading to phytanic acid accumulation in blood and tissues Most common - pigmented retinopathy, with fundal salt and pepper appearance. Other ocular findings - cystoid macular edema and cataract Porphyrias, a group of metabolic disorders of heme biosynthesis characterised by photosensitivity, can also manifest with overlapping dermatologic and ophthalmologic signs, particularly in the cutaneous subtypes. In congenital erythropoietic porphyria and less commonly erythropoietic protoporphyria, ocular involvement may manifest as hyperaemia and chemosis of the interpalpebral conjunctiva, followed by vesiculation, necrosis, and symblepharon formation. The cornea may undergo thinning or perforation from primary blistering or exposure due to cicatricial ectropion, while the sclera may show interpalpebral thinning or acute scleritis [4]. Behçet's disease (BD) is a multisystem vasculitis marked by recurrent oral and genital ulcers with ocular inflammation. Cutaneous signs like erythema nodosum-like lesions, papulopustules, and pathergy positivity may precede or accompany ocular flares. HLA-B51 is strongly linked to ocular BD, especially in Asian males, where eye involvement is more frequent and severe (70%). The hallmark is bilateral posterior uveitis with occlusive necrotizing vasculitis and vascular sheathing, often presenting with redness, photophobia, blurry vision, and complications such as retinitis, neovascularization, and optic atrophy [8]. Table 2 presents other genetic and neurocutaneous disorders that exhibit both skin and eye manifestations but were not included in the indexed review [9, 10]. AR inheritance; mutation in the ABCC6 gene Most common - retinal vascularization leading to retinal detachment. Other ocular changes include cataract, glaucoma, microphthalmia, and optic nerve atrophy AD inheritance; mutation in the APC gene X-LD inheritance; mutation in the PORCN gene Most common- unilateral ocular coloboma in the iris, retina or choroid Others- retinal detachment, microphthalmos or anophthalmos, blue sclera and cataract Lichen planus, though primarily affecting skin and mucosa, may rarely involve the eye as cicatricial conjunctivitis, risking symblepharon, scarring, and vision loss [8]. Among the infections, herpes zoster ophthalmicus, due to varicella-zoster reactivation in the ophthalmic trigeminal branch, presents with a vesicular forehead rash and can cause conjunctivitis, keratitis, uveitis, optic nerve involvement, and potential vision loss [8]. The authors have not addressed ocular manifestations of chronic infections like syphilis and leprosy, which, although clinically relevant, represent extensive multisystem disorders and are beyond the scope of discussion in this letter. Early recognition of overlooked skin–eye syndromes enable timely referral, preventing irreversible ocular complications and disability. A George: conceptualization, literature review, manuscript drafting and editing. The author has read and approved the final manuscript. This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. The author has nothing to report. The author declares no conflicts of interest. Not applicable as no datasets were generated or analysed in this Letter to the Editor. Not applicable as no datasets were generated or analysed in this Letter to Editor.