The risk of sunburn is reason enough for most of us to slather on the SPF 50. But for people with certain genetic disorders, extreme sun sensitivity is a symptom that requires more than just sunscreen.
Think Dracula. Some historians believe one of these conditions, porphyria, is the basis of vampire legends about the mythical man-creature who suffers in sunlight and lives entirely in the dark. But how much of these ancient tales are based in reality? We asked the experts to shed some light on some rare health conditions worsened by sun exposure.
What Is Porphyria Cutanea Tarda?
According to dermatologist Margaret Noland, MD, most porphyrias are genetic disorders caused by a deficiency in the enzymes that break down byproducts of blood formation. There are different variants of porphyria, but the most common is porphyria cutanea tarda, also known as PCT. This disorder affects the skin and causes sun sensitivity.
PCT typically occurs in adults who have a genetic predisposition for the disorder. Certain medications, liver disease, alcohol intake or increased estrogen levels can trigger PCT later in life and cause a symptom flare-up.
There are also more severe inherited variants of porphyria that occur in childhood. “Patients with hereditary variants of porphyria must make significant lifestyle alterations because the symptoms can be so severe,” says Noland. “I had one patient with erythropoietic protoporphyria who became a night guard so that he could work at night and sleep during the day to avoid sun exposure.”
Sun Sensitivity & Other Symptoms of PCT
The symptoms of PCT can vary, yet photosensitivity is one of the telltale signs. When exposed to the sun, patients typically experience:
- Blistering of the skin
- Skin fragility or skin that tears and bruises easily
- Increased hair growth on sun-exposed parts of the body
Those with the more severe childhood variant can develop scarring that may increase their long-term risk for skin cancer later in life. “Porphyrias limit a patient’s functionality and have a huge effect on day-to-day life,” says Noland.
First, symptom management is critical. That means avoiding sun exposure when possible. When patients with PCT venture out, Noland recommends photoprotective clothing and physical sunblock with zinc and titanium.
To treat PCT, it’s key to determine what triggers symptoms. “The first step is removing any inciting factors like medications that may be causing flare-ups,” says Noland. “We also see a lot of PCT with chronic liver disease and alcohol use, so lifestyle changes can have a huge impact.”
Some medication can be effective at managing PCT, but one of the most common treatments is phlebotomy, or the removal of blood from the body. This spurs the production of new red blood cells and reduces iron levels, which can put PCT in remission.
What Is Xeroderma Pigmentosum?
A defect in the body’s DNA repair system causes xeroderma pigmentosum (XP), another rare genetic disorder. Normally, the body repairs cell damage that happens when skin is exposed to ultraviolet (UV) rays. But in people with XP, that repair process doesn’t happen.
Xeroderma Pigmentosum Symptoms
The symptoms of XP typically appear in infancy or early childhood. “A severe sunburn after a very short period of sun exposure is usually the first sign,” says dermatologist Barrett Zlotoff, MD. “Children with XP can develop freckles and have the same kind of skin changes that older people develop over time from sun damage.” These skin changes may include:
- Dark spots
- Rough patches
- Painful open sores
- Pre-cancers and skin cancers even in children under five years old
XP also makes the eyes more sensitive, so they may be red and bloodshot after sun exposure.
“Later, kids can even get neurological symptoms depending on the type of XP,” adds Zlotoff. “Symptoms include poor coordination, muscle spasms, developmental delays and deafness.”
Xeroderma Pigmentosum Treatment
There is no cure for XP, so treatment involves preventing and managing symptoms. Priority number one: avoiding UV light exposure.
Unusual response to sun exposure?
Make an appointment today with a UVA dermatologist.
“It’s important to filter out all UV light to reduce the risk of skin cancer,” says Zlotoff. “These kids basically need to be totally protected, so the windows on their cars and homes have special filters. They wear sunscreen all the time, but they also need long sleeves, hats, sunglasses and gloves. Many have custom-made suits, almost like space suits, with plastic shields that go over their faces, so they can see out but UV light can’t get in.”
Skin cancer and severe neurological involvement can limit the lifespan of kids with XP. However, with early diagnosis and rigorous sun protection, many can live normal lives.
“Most kids go to school and live a normal life, but they have to dress for it,” says Zlotoff. “It’s socially difficult, obviously, walking through the world with protective suits on. But a lot of parents do a lot to try to educate teachers and other kids at school. There are camps where these kids can go and do all of the regular camp activities at night. And there is a great XP family support group online.”