Xenoderma pigmentosum is a genetic disorder that features with impossibility of proper repair after the damage caused by ultraviolet light. The exposure to sunlight in patients suffering from this horrible disease is banned for life. The lethal outcome is mainly caused by severe skin malignancies these people are prone to. Skin aging is accelerated as well. Xenoderma pigmentosum occurs six times more in Japanese population than in other people. Both genders are affected equally.
Patophysiology of the disease is based on improper repair of DNA after its exposure to the sunlight. This autosomal recessive disorder leads to permanent damage of DNA. If parts of DNA in charge with tumor suppression are affected one can develop malignancies mainly skin tumors such as melanoma and basal cell carcinoma.
Mother and father of a child who gets xenoderma pigmentosum must be carriers of the defected gene. Those parents whose child is suffering from this dreadful disease are at risk to have one more child with xenoderma pigmentosum. That chance is 1: 4.
The disease presents with three stages. The baby is born with normal skin and no specific skin changes.
However after the first exposure to the sun symptoms and signs of the disease become obvious. As mainly face and uncovered parts of the body gets in contact with ultraviolet light these are predilection places of the first skin changes. The reddening together with freckles occurs. The exposed skin is spotted in dark specks and even scalds are possible. In worst cases the entire body is covered with these changes. In case of winter months when the sun does not shine regularly skin changes may reduce in intensity and some may disappear.
Prolonged exposure to the sun leads to even greater damage and the stage two of the disease. Poikilodermia is specific for this stage. This skin condition features with pigmentous and atrophic changes of the skin. All together they lead to skin discolorations. The skin becomes thinner and bloody spots tend to make formations that resemble spider web.
The third and final stage includes the development of solar keratosis and skin cancers. This stage may occur in early childhood if kid is not protected from the sun. Sqamous cell carcinoma basal carcinoma and especially melanoma are three skin cancers that commonly affect people suffering from xenoderma pigmentous. Additionally problems with eyes occur. They become more sensitive to sunlight. Eye irritation and conjunctivitis occur more often. Even eyes can get affected by malignant diseases.
These people may develop additional neurological problems such as muscle spasms problems with coordination postponed development and even deafness.