Xeroderma Pigmentosum

Xeroderma Pigmentosum

 Key points
Condition results in high sensitivity to sunlight/ultraviolet light which causes skin aging and a high propensity for skin cancer.
Condition is autosomally recessive, affecting all genders and races.
Disease progresses in three varying stages of intensity — starting with a reddening of sun-exposed areas and progressing to common forms of skin cancer.
Diseases can result in additional eye and neurological disorders.

Xeroderma pigmentosum or XP is a very rare skin disorder where a person is highly sensitive to sunlight resulting in premature skin aging and a propensity to Skin cancer development. Frequently, this is caused by a cellular hypersensitivity to ultraviolet light due to a DNA repair system defect. XP is an autosomally recessive inherited disease, which means two parents who carry the gene but do not show signs or symptoms can still pass the disease to their offspring, resulting in varying levels of severity of XP. Typically these severities are classified by lettering A-G. Xeroderma pigmentosum affects all genders and races.

Xeroderma pigmentosum causes an inability to replenish or repair ultraviolet damaged skin, which often results in cancerous skin cells or cell death. The disease progresses through three stages. Stage one occurs in early infancy (6 months after birth). Areas exposed to sun will show reddening of the skin with freckling and scaling, and occasionally irregular dark spots. The skin changes progress to the neck and lower legs, and in severe cases, the trunk. Over winter months, the changes may diminish. Continued sun exposure will result in stage two, characterized by poikiloderma — irregular patches of lightened or darkened skin, a spider-web-like collection of blood spots and vessels seen through the skin, and a thinning of the skin. The third stage is development of Solar keratoses and skin cancers, occurring as early as age 4 and in the most frequently sun-exposed areas, such as the face. Most common skin cancers (Basal cell carcinoma, squamous cell carcinoma, and Melanoma) are more frequent in patients with XP.

Xeroderma pigmentosum can also cause eye and neurological problems in some patients. 80% of XP patients suffer eye problems such as photophobia (painful sensitivity to the sun), conjunctivitis or frequent irritation, bloodshot and cloudy vision, or growths on the eyes of a cancerous or non-cancerous nature. Neurological problems are less frequent — only 20% — but can result in mild or severe spasticity, poor coordination, developmental delay, deafness, and short stature. These problems may develop in late childhood or adolescence, worsening over time.

Different Diagnosis (Other conditions with similar appearance)
Acanthosis nigricans
Bloom syndrome (Congenital telangiectatic erythema)
Cockayne Syndrome
Ephelides (Freckles)
Hartnup disease
Hydroa vacciniforme
Werner syndrome

Diagnosis
Key Points
Usually detected in early infancy.
Child may show signs of severe Sunburn after first exposure to sunlight.
Blood and skin samples can be tested for poor DNA repair.

Treatment
There is no cure for Xeroderma pigmentosum, just preventative measures.
Avoiding sun exposure is the key precautionary measure
Frequent examinations can help with prevention or early diagnosis of the skin disorders/cancers.
* Medications are mostly used to combat the advanced stage symptoms.

There is no cure for Xeroderma pigmentosum. The main goal of treatment is to protect oneself from UV exposure and thus prevent the damaging effects on the skin. Sun avoidance is perhaps the most important precautionary measure: wearing protective clothing, Sunscreens with SPG of 30 or higher on all exposed area, avoidance of outdoor activities during daylight. Frequent skin examinations for suspicious growths or spots as well as dermatologist appointments can help with early detection or warnings of cancers. Eye exams and neurological testing will also determine additional dangers or symptoms. There are therapies and medications that will also assist with the advanced dangers of the disease. Solar keratoses may be treated by cryotherapy or 5-fluorouracil cream. Many of the skin cancers can be treated with Isotretinoin or vitamin A derivatives.