Summary about Disease
Xeroderma pigmentosum (XP) is a rare, inherited genetic disorder characterized by an extreme sensitivity to ultraviolet (UV) rays from sunlight and other sources. This sensitivity results in a greatly increased risk of skin cancer, eye damage, and neurological problems. People with XP have a reduced ability to repair DNA damage caused by UV light.
Symptoms
Extreme sensitivity to sunlight: Severe sunburn after brief exposure, even on cloudy days.
Dry skin (xeroderma): Rough, scaly, and often itchy skin.
Freckling: Excessive freckling, especially in sun-exposed areas.
Changes in pigmentation: Irregular areas of increased or decreased skin color (hypo- or hyperpigmentation).
Telangiectasias: Small, dilated blood vessels on the skin.
Eye problems: Sensitivity to light (photophobia), corneal clouding, and increased risk of eye cancers.
Skin cancers: High risk of developing basal cell carcinoma, squamous cell carcinoma, and melanoma at a young age.
Neurological problems: In some cases, progressive neurological problems such as developmental delays, intellectual disability, hearing loss, seizures, and difficulty coordinating movements (ataxia) may occur.
Causes
XP is caused by mutations in genes involved in nucleotide excision repair (NER), a DNA repair mechanism that corrects UV-induced DNA damage. These mutations are inherited in an autosomal recessive pattern, meaning that both parents must carry a copy of the mutated gene for a child to be affected. There are several different genes that, when mutated, can cause XP.
Medicine Used
4. Medicine used There is no cure for XP, and treatment focuses on preventing further UV exposure and managing symptoms.
Strict sun protection: This is the most important aspect of management. Includes sun-protective clothing, wide-brimmed hats, sunglasses, and high SPF sunscreen (SPF 30 or higher) applied frequently.
Regular skin exams: Frequent monitoring by a dermatologist to detect and treat skin cancers early.
Surgical removal of skin cancers: Standard treatment for skin cancers.
Topical medications: Creams or ointments to treat actinic keratoses (precancerous skin lesions).
Artificial tears: For dry eyes.
Treatment for neurological problems: Supportive care and therapies to manage neurological symptoms, if present.
Nicotinamide: Some studies suggest it may reduce the risk of non-melanoma skin cancers.
Is Communicable
No, Xeroderma pigmentosum is not communicable. It is a genetic disorder and cannot be spread from person to person.
Precautions
Avoid sunlight: Stay indoors during peak sunlight hours (10 AM to 4 PM).
Use sun-protective clothing: Wear long sleeves, long pants, and wide-brimmed hats when outdoors.
Apply sunscreen: Use a broad-spectrum sunscreen with an SPF of 30 or higher, and apply it generously and frequently.
Protect your eyes: Wear sunglasses that block 100% of UVA and UVB rays.
Monitor skin closely: Check your skin regularly for any new or changing moles or lesions.
Regular medical checkups: Regular visits to a dermatologist and ophthalmologist are crucial for early detection and treatment of complications.
Protect from other UV sources: Avoid tanning beds and other artificial sources of UV radiation.
Home and school modifications: UV-filtering film on windows in homes and schools can help reduce UV exposure indoors.
How long does an outbreak last?
XP isn't characterized by outbreaks in the typical sense. It's a chronic condition. The skin damage accumulates over a lifetime with continued UV exposure. Skin cancers, once they develop, require specific treatment and do not resolve on their own without intervention. Sunburns, of course, will heal in days to weeks depending on severity, but the underlying genetic defect remains.
How is it diagnosed?
Clinical examination: Based on the characteristic symptoms, such as extreme sun sensitivity and skin changes.
Family history: A family history of XP can raise suspicion.
Skin biopsy: A small sample of skin is taken and examined under a microscope to look for signs of DNA damage and cancer.
Genetic testing: Blood or tissue samples can be tested to identify mutations in the genes known to cause XP.
Cellular assays: Tests to measure the ability of cells to repair UV-induced DNA damage.
Timeline of Symptoms
9. Timeline of symptoms
Infancy/Early Childhood: Extreme sensitivity to sunlight is often the first noticeable symptom. Severe sunburn after minimal sun exposure. Excessive freckling appears early in sun-exposed areas.
Childhood/Adolescence: Dry skin, pigment changes, and telangiectasias develop. The risk of skin cancer begins to increase dramatically. Eye problems may become apparent. Some individuals may start to show neurological symptoms.
Adulthood: Continued accumulation of sun damage leads to a high risk of skin cancers. Neurological problems, if present, may progress.
Important Considerations
Genetic counseling: Important for families with a history of XP to understand the risk of recurrence.
Psychological support: Living with XP can be challenging, and psychological support may be beneficial.
Education: Patients and families need comprehensive education on sun protection and the importance of regular medical checkups.
Early diagnosis: Early diagnosis and strict sun protection are crucial for minimizing the long-term health consequences of XP.
Research: Ongoing research is focused on developing new treatments for XP, including gene therapy approaches.