Drug Information Portal. U.S. National Library of Medicine. "Almotriptan malate". Drug Information Portal. U.S. National Library of Medicine.
By region, it affects about 1 in 370 in India, 1 in 20,000 in Japan, 1 in 250,000 people in the United States and 1 in 430,000 in Europe. It occurs equally commonly in males and females. Xeroderma pigmentosum was first described in the 1870s by Moritz Kaposi. In 1882, Kaposi coined the term xeroderma pigmentosum for the condition, referring to its characteristic dry, pigmented skin. Individuals with the disease have been referred to as "children of the night" or "moon children". Signs and symptoms
Signs and symptoms of xeroderma pigmentosum may include:
Severe sunburn when exposed to only small amounts of sunlight. These often occur during a childs first exposure to sunlight. Development of many freckles at an early age
Rough-surfaced growths (solar keratoses), and skin cancers
Eyes that are painfully sensitive to the sun and may easily become irritated, bloodshot and clouded
Blistering or freckling on minimum sun exposure
Telangiectasia (spider veins)
Limited growth of hair on chest and legs
Scaly skin
Xeroderma (dry skin)
Irregular dark spots on the skin
Corneal ulcerations

Genetics
One of the most frequent defects in xeroderma pigmentosum is an autosomal recessive genetic defect in which nucleotide excision repair (NER) enzymes are mutated, leading to a reduction in or elimination of NER. If left unchecked, damage caused by ultraviolet light can cause mutations in individual cells DNA. The causes of the neurological abnormalities are poorly understood and are not connected with exposure to ultraviolet light.