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5 of the World's Rarest Skin Conditions

Harlequin Ichthyosis

Harlequin ichthyosis affects newborns -- they are born with thick, hard plates of skin covering their body. These plates are separated by deep cracks.

This extremely rare condition makes it difficult for the affected babies to control water and fluid loss, resulting in severe dehydration. Babies with harlequin ichthyosis also have trouble moving, breathing, fighting off infection and regulating their body temperature [source: NIH]. With such complications, it is very common for an infant to die within weeks after birth.

Doctors believe that harlequin ichthyosis is a genetic disorder where a mutation in the ABCA12 gene affects the development of the epidermis [source: NIH]. More than 100 cases have been reported around the world [source: Prendiville].

Though some babies have been known to survive with the condition, they require intensive care in an incubator where such things as temperature and bodily fluids can be monitored and nutrients can be quickly replaced. Even for patients who can survive past infancy, harlequin ichthyosis is incurable, and they would have to struggle with it their entire life.

One person surviving the disease into his teens has said he hangs on to life by consuming 7,500 calories a day to make up for the lost nutrients of shedding skin 10 times faster than the average person and moisturizes his skin seven times a day [source: 10news].