Hydroa vacciniforme is a rare type of chronic photodermatitis that tends to affect children. Children with this condition develop recurrent rashes in the days following sun exposure. Here are four things parents need to know about hydroa vacciniforme.

What are the signs of hydroa vacciniforme?

If your child has hydroa vacciniforme, you'll notice that they develop lesions on their skin between 30 minutes and 2 hours after being exposed to the sun. Sun-exposed areas of skin like the face and backs of the hands are generally affected.

These lesions first present as fluid-filled bumps but later become umbilicated, meaning that the centers become indented. These umbilicated lesions then become crusty and necrotic, before finally healing and leaving behind depressed scars that are lighter than the rest of your child's skin.

These lesions will generally first appear in the spring, with recurrences throughout the summer, though in regions that are warm and sunny year-round, the lesions can occur throughout the year.

What causes it?

While it's clear that the sun is the trigger for this condition, researchers still don't know why this happens. In some reported cases, the disorder runs in families, which suggests that there may be a genetic cause for the condition. It's also been linked to hematopoietic malignancies, which include cancers like lymphoma and leukemia. Another suggested cause is the Epstein-Barr virus, the virus that causes mononucleosis. More research is required to determine why this condition occurs.

Do children grow out of it?

Fortunately, hydroa vacciniforme usually goes away by itself during adolescence. However, this doesn't always happen, and some children will still have the condition during adulthood. However, since the condition causes serious cosmetic problems and is also painful, it needs to be managed until it goes away.

How is it managed?

The main way to manage this condition is to keep your child out of the sun, according to NIH. Your child needs to wear long-sleeved shirts and long pants when they are outdoors, as well as a wide-brimmed hat to protect their face and neck. In addition to this protective clothing, sunscreen also needs to be worn.

If avoiding the sun isn't enough, medications can also be used. Your child's pediatrician may prescribe systemic corticosteroids, which work by controlling inflammation. Antiviral medications can also be useful if your child is infected with the Epstein-Barr virus.

If you think your child has hydroa vacciniforme, take them to a pediatrician right away.