A disorder in which the skin is very rough
. The most common
form is known also as ichthyosis simplex
, in which large corrugated papery scales
form on the skin (which is deficient
in sebaceous glands and sometimes also in sweat glands).
Xeroderma pigmentosum is a rare disease, usually appearing in childhood, in which the skin atrophies (wastes away) and wrinkles. There is a familial tendency. Sufferers have photophobia (abnormal sensitivity of the eyes to light), and the warty and “keratolytic” lesions of the disease quickly become malignant if exposed to sunlight. Sufferers must be protected from the sun. The skin has the appearance of very old skin even in young people.