Harlequin Ichthyosis

 Harlequin ichthyosis is characterized by a thickening of the keratin layer in fetal human skin. Infants with this condition are born with very hard, thick skin covering most of their bodies. The skin forms large diamond-shaped plates separated by deep cracks (fissures). It may also cause the eyes, ears, mouth and other appendages to contract abnormally. This makes it difficult for them to feed.

These skin abnormalities affect the shape of the eyelids, nose, mouth, and ears, and restrict movement of the arms and legs. Restricted movement of the chest can lead to breathing difficulties and respiratory failure. The skin normally forms a protective barrier between the body and its surrounding environment. The skin abnormalities associated with harlequin ichthyosis disrupt this barrier, making it more difficult for affected infants to control water loss, regulate their body temperature, and fight infections.

Infants with harlequin ichthyosis often experience an excessive loss of fluids from the body and develop life-threatening infections during the newborn period. Harlequin Ichthyosis results in problems with temperature regulation, dehydration, and the body's ability to fight infections. Only about fifty percent of infants born with the disorder survive. This condition is likely inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations.

Treatment is largely supportive and involves optimizing fluid, electrolyte, and nutritional repletion, aggressive use of emollients, and environmental measures to decrease transepidermal water loss. Treatment of harlequin babies can be done with a battery of medication ranging from oral retinoids to antiseptics and topical paraffin ointments to soften the skin. In general, harlequin fetuses do not survive for long. There have been improvements in care, most notably the drug Isotrex.