This case report describes the use of genotype-guided medical treatment of an arteriovenous malformation in a child.

Arteriovenous malformations are a vascular anomaly typically present at birth, characterized by an abnormal connection between an artery and a vein (bypassing the capillaries). These high flow lesions can vary in size and location. Therapeutic approaches are limited, and AVMs can cause significant morbidity and mortality. Here, we describe our current understanding of the pathogenesis of arteriovenous malformations based on preclinical and clinical findings. We discuss past and present accomplishments and challenges in the field and identify research gaps that need to be filled for the successful development of therapeutic strategies in the future.

Food allergy (FA) is now one of the most common chronic diseases of childhood often lasting throughout life and leading to significant worldwide healthcare burden. The precise mechanisms responsible for the development of this inflammatory condition are largely unknown; however, a multifactorial aetiology involving both environmental and genetic contributions is well accepted. A precise understanding of the pathogenesis of FA is an essential first step to developing comprehensive prevention strategies that could mitigate this epidemic. As it is frequently preceded by atopic dermatitis and can be prevented by early antigen introduction, the development of FA is likely facilitated by the improper initial presentation of antigen to the developing immune system. Primary oral exposure of antigens allowing for presentation via a well‐developed mucosal immune system, rather than through a disrupted skin epidermal barrier, is essential to prevent FA. In this review, we present the data supporting the necessity of (1) an intact epidermal barrier to prevent epicutaneous antigen presentation, (2) the presence of specific commensal bacteria to maintain an intact mucosal immune system and (3) maternal/infant diet diversity, including vitamins and minerals, and appropriately timed allergenic food introduction to prevent FA.

Epidermal differentiation disorders (EDDs) encompass inherited conditions characterized by abnormal epidermal differentiation, including nonsyndromic and syndromic subtypes with more extensive cutaneous involvement or palmoplantar keratoderma. Nonsyndromic EDDs (nEDDs) are defined as disorders that primarily affect large areas of skin and adnexal structures without alterations in extracutaneous tissues resulting from the underlying genetic change. To facilitate the development of targeted therapies and to provide clinicians with clearer therapeutic guidance, we have developed a new nomenclature for EDDs that includes the causative altered gene and the nEDD subgroup designation, sometimes with a clinical or histological descriptor or acronym. Historically, many nEDDs have been named on the basis of phenotypic characteristics or associations that are now considered outdated or inappropriate. For example, the term ‘harlequin ichthyosis’ evokes potentially stigmatizing images. Similarly, the word ‘ichthyosis’ is derived from the Greek ichthys, meaning fish, and the Greek hystrix, meaning porcupine, further emphasizing the need to abandon derogatory terminology. As a result, the clinical relevance of the previous classification, which included eponymous and/or descriptive titles, has diminished. In the new, gene-based classification, old terms considered pejorative, such as ichthyosis, vulgaris, hystrix and harlequin have been eliminated and eponyms have been replaced. Among the 53 genetically distinct nEDDs are conditions formerly known as autosomal recessive congenital ichthyosis, erythrokeratodermia variabilis et progressiva, Hailey–Hailey disease and Darier–White disease. This review outlines the updated nomenclature and classifications of nEDDs, linked to detailed clinical descriptions and representative photographs to guide practitioners.