P142 Making the invisible visible: national epidemiology reporting of rare dermatological diseases in England

Abstract

Many rare skin conditions cause significant morbidity, but ­population-level epidemiological data are limited, impairing service planning. We analysed national registry data on rare dermatological conditions in England. Prevalence data were collated from Rare Condition Registration Statistics (2022) and published reports on epidermolysis bullosa (EB) and congenital ichthyosis, with incidence data from the Get Data Out (GDO) programme. Prevalence was reported per million using midyear England population denominators. The prevalence per million (95% confidence interval) varied across conditions: systemic lupus erythematosus 747 (740–754), giant cell arteritis 685 (678–692), polymyositis 316 (311–321), scleroderma 205 (201–208), granulomatosis with polyangiitis 111 (108–114), dermatomyositis 46.5 (44.8–48.3), cutaneous T-cell lymphoma 43.5 (41.8–45.3), eosinophilic granulomatosis with poly­angiitis 41.7 (40.0–43.4), Merkel cell carcinoma 29.7 (28.3–31.1), microscopic polyangiitis 27.1 (25.7–28.5), Langerhans cell histiocytosis 13.6 (12.6–14.6) and juvenile idiopathic inflammatory myopathy 9.1 (8.4–10.0). Subtype-specific prevalence (per million with 95% confidence interval) for inherited genodermatoses, ordered from most to least prevalent, showed EB unspecified 25.0 (23.7–26.3), EB simplex 13.3 (12.3–14.2), dystrophic EB 8.9 (8.1–9.7), other 4.1 EB (3.6–4.6) and severe junctional 0.5 (0.3–0.7). For ichthyosis the data showed ichthyosis unspecified 27.0 (25.7–28.4); ichthyosis vulgaris 8.1 (7.4–8.9); congenital bullous ichthyosiform erythroderma 6.2 (5.6–6.9); X-linked, lamellar and other congenital ichthyosis each 5.2 (4.6–5.8) and harlequin ichthyosis 4.1 (3.6–4.7) (Akayima M, Choate K, Hernández-Martín A et al. Nonsyndromic epidermal differentiation disorders: a new classification toward pathogenesis-based therapy. Br J Dermatol 2025; 193: 619–41). GDO incidence data captured 22 dermatology-related malignancies, including cutaneous sarcomas and appendageal skin cancers. This population-level report describes an incomplete but important review of rare dermatological conditions in England with the aim to gain momentum and improve representation. Robust national data are essential for supporting research, clinical care and service planning.