Xeroderma pigmentosum clinical practice guidelines.

Xeroderma pigmentosum (XP) is a genetic photosensitive disorder in which patients are highly susceptibe to skin cancers on the sun-exposed body sites. In Japan, more than half of patients (30% worldwide) with XP show complications of idiopathic progressive, intractable neurological symptoms with poor prognoses. Therefore, this disease does not merely present with dermatological symptoms, such as photosensitivity, pigmentary change and skin cancers, but is "an intractable neurological and dermatological disease". For this reason, in March 2007, the Japanese Ministry of Health, Labor and Welfare added XP to the neurocutaneous syndromes that are subject to government research initiatives for overcoming intractable diseases. XP is one of the extremely serious photosensitive disorders in which patients easily develop multiple skin cancers if they are not completely protected from ultraviolet radiation. XP patients thus need to be strictly shielded from sunlight throughout their lives, and they often experience idiopathic neurodegenerative complications that markedly reduce the quality of life for both the patients and their families. Hospitals in Japan often see cases of XP as severely photosensitive in children, and as advanced pigmentary disorders of the sun-exposed area with multiple skin cancers in adults (aged in their 20-40s), making XP an important disease to differentiate in everyday clinical practice. It was thus decided that there was a strong need for clinical practice guidelines dedicated to XP. This process led to the creation of new clinical practice guidelines for XP.