Harlequin Ichthyosis: A Comprehensive Review of Pathogenesis, Diagnosis, and Management

Harlequin ichthyosis, one of the rarest and most severe skin disorders, is mainly characterized by extreme hyperkeratosis, severely impairing the natural barrier function of the skin. This congenital disease results from a mutation in the ABCA12 gene responsible for lipid transport, whereby healthy skin development is assured. Harlequin ichthyosis is an autosomal recessive condition that requires parents to carry a defective gene copy for the disorder to manifest in their offspring. Babies born with Harlequin ichthyosis have thick skin plates that crack and flake off; they easily become dehydrated, infected, and may suffer from respiratory complications. With new improvements in neonatal care and systemic therapy, notably retinoid therapy, infants’ survival rates have improved. This review provides an inclusive overview of the pathophysiology, clinical features, diagnostic methods, management, and potential future therapies for Harlequin ichthyosis. In addition, a discussion on genetic counseling and its importance in managing family risk factors is also included, as well as a look into cutting-edge research focused on gene therapy and potential curative treatments.