Kindler syndrome (KS) is the fourth major type of epidermolysis bullosa (EB), besides simplex, junctional and dystrophic forms, and is characterized by skin fragility and blistering at birth followed by development of photosensitivity and progressive poikilodermatous skin changes.
The disease usually manifests at birth with trauma-induced skin blistering that is more prominent on extremities and tends to regress with age, becoming rare in adulthood. Healing of blisters occurs with minimal scarring. With age, additional skin findings are observed: (i) in most patients, photosensitivity with erythema and photo-induced blisters is obvious since early childhood and often diminishes after adolescence, (ii) progressive skin poikiloderma (atrophy, telangiectases, and reticular pigmentation) manifests from childhood and is predominantly localized to the face and neck, and (iii) skin atrophy is localized to hands and feet in the first years of life but becomes generalized by adolescence. Blisters also affect the mucosae. In the oral cavity, chronic gingivitis and periodontitis are frequent and prominent features in adulthood. Esophageal strictures, causing dysphagia and requiring repeated dilatations, frequently develop in adulthood. Anal (bleeding, stenosis), urogenital (urethral bleeding, meatal stenosis), and ocular (ectropion) involvement has also been described. The frequency of these manifestations increases with age. An additional frequent feature is digit webbing/partial pseudosyndactyly. Laryngeal and intestinal involvement, the latter manifesting with severe colitis, are rare. Other features may include: skin xerosis and fine scaling, palmoplantar hyperkeratosis, milia formation, nail dystrophy, constricting bands of pseudoainhum type, orogenital leukokeratosis. Finally, KS patients present an increased susceptibility to the development of squamous cell carcinomas (SCC): in a recent case series skin cancer affected 70% of the patients older than 45 years. Prevalence is unknown. More than 250 cases have been reported to date.