What is XP – Xeroderma Pigmentosum?
Xeroderma Pigmentosum (XP) is a rare skin condition and a genetic disorder that affects the body’s ability to tolerate UV rays from the sun or any other sources. It is caused by cellular hypersensitivity to UV radiation and affects the skin and eyes particularly, and in some cases, it can damage the nervous system.
The symptoms of XP typically develop in childhood, and it’s necessary to consult a doctor if an infant’s skin shows any signs of UV damage, such as blister formation, after getting exposed to the sun for just a few minutes.
Skin damage like burns, blisters, and freckles, which form due to exposure to the sun, is more common in people with XP.
What are the symptoms?
XP (xeroderma pigmentosum) patients are highly susceptible to the DNA-damaging effects of UV rays from the sun, with symptoms affecting the skin, eyes, and neurological system.
Symptoms affecting the skin:
- After minimal exposure to the sun, most of the patients with Xeroderma Pigmentosum experience blistering burns on the skin exposed to the sun. This can happen even after being exposed for about 10 minutes
- Severe skin burns
- Extreme levels of skin pigmentation that can either increase or decrease
- Skin cancer
- Flaky and dry skin that represents a parchment paper
- Freckle formation at an early stage
- Spider veins
- Thinning of skin
- Actinic keratosis – precancerous skin signs
Xeroderma Pigmentosum: Symptoms affecting eyes:
- Severe eye inflammation, especially in the cornea
- Eyelids that turn abnormally outward (ectropion)or inward (entropion)
- Cloudiness of eye lens
- Inflammation of the eyelid lining, the white part of the eye (sclera) and corneas
- Excessive tear production
- Photophobia (pain when exposed to light), a common symptom of light sensitivity
- Redness in the eyes
- Irritation that does not go away
- Dryness in eyes
- Feeling that ‘something is in the eye’ often
Symptoms affecting the nerves:
- Progressive neuro-degeneration is seen in some patients with Xeroderma Pigmentosum
- The size of the head becomes smaller, and changes in the brain’s structure (acquired microcephaly) is seen
- Fading deep tendon reflexes and, in most cases, are non-existent
- Damage to the inner ear nerves resulting in deafness
- Learning and developmental difficulties
- Tightness in the muscles
- Muscle control and coordination issues (ataxia)
- Impaired swallowing and/or paralysis of the vocal cords
How is it caused?
Xeroderma Pigmentosum is a recessive autosomal genetic disease. Every gene is passed down in two copies, one from each parent. Genes are tiny pieces of DNA that make up a chromosome.
The term, ‘recessive’ refers to the fact that the problem must be present in both copies of the gene for the child to be affected. The term “autosomal” refers to a gene that is found on a non-sex-determining chromosome.
XP can be caused by nine different genes that aren’t acting correctly. Several of these genes play a role in DNA damage repair. Normally, skin cells heal UV damage before it becomes an issue, but in patients with XP, this process is disturbed.
Xeroderma Pigmentosum is more prevalent in some geographic, isolated areas. This, in part, could be due to consanguinity, which means that both parents are blood relatives like cousins. If parents share a genetic background, the chances of passing XP to their children will increase.
Neurologic abnormalities, skin cancer and eye abnormalities are the most common complications of XP.
How is it diagnosed?
Xeroderma Pigmentosum is extremely rare, and before diagnosing this condition, the physician would first rule out the possibility of another medical condition causing the symptoms.
One of the most common ways to diagnose XP is to check for any family history of this condition and check if the patient is a carrier through a blood sample test.
For pregnant patients, the physician may administer a test called amniocentesis, which detects the presence of XP and other genetic diseases in the fetus.
What is the outcome of xeroderma pigmentosum?
XP patients have an increased risk of developing skin cancer. Children suffering from XP and who don’t use any form of sun protection have a high risk of developing skin cancer by the age of 10. Skin cancer, caused by XP, can occur on the face, lips, scalp, tip of the tongue and also on the eyelids.
Patients suffering from XP can also develop other serious conditions like brain tumors, and cigarette smokers who suffer from XP have a higher chance of developing lung cancer as well.
What are the remedies to treat XP?
There is no treatment for Xeroderma Pigmentosum found yet. However, the effects of the disease can be reduced by following certain precautionary measures for the eyes, skin and nerves. Some of the preventive measures are:
- UV (ultraviolet) protection – Using protective gears like hats, hoods with UV-blocking face shields, long sleeves, leggings, and gloves
- Applying high UVA/UVB protection (SPF) sunscreens
- Wearing sunglasses with side shields that protect from UV rays
- Testing the patient’s surroundings (e.g., home, school, and job) for UV levels with the help of UV light metres to identify areas of higher UV and sources of dangerous UV rays that may be removed from the environment.
- Using UV blocking film on windows in Xeroderma Pigmentosum sufferers’ homes, schools, offices, and automobiles.
- Intake of vitamin D supplements
Patients are also advised to follow preventive care for eyes, skin and nerves, and regular checkups to diagnose any underlying condition at an early stage and get them treated.
Due to it’s rare occurrence, Xeroderma pigmentosum (XP) can be challenging to diagnose and treat, especially if this condition has led the patient to develop another serious condition like skin cancer. Hence, it’s important to spread awareness on this rare skin disorder, and treat any early signs or symptoms of this condition before it becomes worse.