Harlequin ichthyosis

Harlequin ichthyosis is a severe genetic disorder that affects the skin. Infants with this condition are born prematurely with very hard, thick skin covering most of their bodies. The skin forms large, diamond-shaped plates that are separated by deep cracks (fissures). These skin abnormalities affect the shape of the eyelids, nose, mouth, and ears, and limit movement of the arms and legs. Restricted movement of the chest can lead to breathing difficulties and respiratory failure in babies with harlequin ichthyosis. Affected infants also have feeding problems.

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 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 (dehydration) and develop life-threatening infections in the first few weeks of life. 

Following the newborn period, the hard, skin plates are shed and the skin develops widespread scales and redness.

It used to be very rare for affected infants to survive the newborn period. However, with intensive medical support and improved treatment, babies with this disorder now have a better chance of living into childhood and early adulthood.