[Systemic therapies for pediatric patients with ichthyosis]

Hereditary ichthyoses are rare, etiologically and clinically heterogeneous epidermal keratinization disorders that are characterized by excessive dryness with scaling of the skin and in some cases increased palmoplantar keratinization. Additional inflammation is common and there are forms associated with blistering. In terms of differential diagnosis, ichthyoses with associated erythroderma in particular must be distinguished from primary atopic diseases with immunodeficiency.

The aim is to provide basic knowledge of the classification and nomenclature of ichthyoses and of current guideline-based and approved therapies. Readers should also be made aware of the difficulties of treating this rare skin disease in children and adolescents with only a few approved therapies. New and innovative treatment options are described and thereafter the reader should be able to confidently identify potential patients for approved and novel therapies.

The current guidelines as well as the current literature and expert consensus on systemic therapies for ichthyosis with a focus on pediatric patients are discussed.

Precise phenotyping, endotyping and the inclusion of the patient's expectations with regard to therapy currently allow comprehensive treatment to alleviate symptoms with good interdisciplinary cooperation. In the absence of causal therapy options, hereditary ichthyosis usually requires lifelong symptomatic individualized therapy. The basis of therapy is local therapy. Acitretin is currently the only approved systemic therapy. Pathophysiologically driven and therefore personalized and targeted therapies, in the form of topical replacement proteins or lipids, small molecules with a variety of target structures and biologics to address inflammation, are the focus of new therapeutic options. Causal therapeutic approaches, such as gene therapies, are currently under development.