Focal Dermal Hypoplasia: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Focal Dermal Hypoplasia?
A dermatologist usually leads care for the skin signs. Because the condition can affect many parts of the body, care often involves a team that may include an eye doctor, a dentist, an orthopedist, and a geneticist. A primary care doctor can help coordinate these visits.
What it is
Focal dermal hypoplasia is a rare condition that a person is born with. The name means that some small areas of skin are missing one of their normal layers. The skin in these spots is thin, so the fat underneath may show through and look reddish or wrinkled. The condition can also affect the bones, teeth, hair, nails, and eyes.
Symptoms
The most visible sign is thin patches of skin, often on the arms and legs. These patches may look dimpled, reddish, or yellow, and small lumps of fat can poke through them. Other signs include joined or smaller fingers or toes, small or missing teeth, ridged nails, and sparse hair. Some people have vision problems or growth delays.
Causes and who gets it
Focal dermal hypoplasia is caused by a change in a gene called PORCN, on the X chromosome. Most cases happen as a new gene change that neither parent carries. It almost always affects girls and women, because the change is usually much more serious in boys.
How doctors diagnose it
Doctors usually diagnose the condition by looking at the skin and other physical signs. A genetic blood test can confirm the diagnosis by finding the PORCN gene change. In some families, testing can be done before birth.
Treatment
There is no cure, but treatment can address each symptom. Skin patches and fat bumps can sometimes be improved with surgery. Other treatments may include dental care, glasses or eye surgery, and therapy or surgery for hand and bone differences. A team of specialists works together on a plan for each person.
When to see a doctor
Talk to a doctor if a baby has thin, dimpled, or missing patches of skin at birth, or if fingers, toes, teeth, or eyes look unusual. Any skin patch that becomes irritated, painful, or infected should also be checked.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either one can manage routine care, including checkups, skin monitoring, referrals, and general health needs. When specialized care is needed, they refer the patient to the right specialist and help coordinate visits.
Common questions
Is focal dermal hypoplasia life threatening?
For most girls and women, the condition is not life threatening. Boys with the condition often have more serious health problems. Families should talk with their doctors about what to expect.
Can it be prevented?
Most cases happen as a new gene change. There is no known way to prevent it. Families who have one child with the condition may want to meet with a genetic counselor.
Will my child's skin patches go away?
The thin skin patches usually do not disappear on their own. Some related problems, such as small fat bumps, can be treated with surgery if they bother the child.
How common is this condition?
Focal dermal hypoplasia is very rare. Only a few hundred cases have been reported in the medical literature.
Sources
- NIH Genetic and Rare Diseases Information Center - Focal dermal hypoplasia
- MedlinePlus Genetics - Focal dermal hypoplasia
- National Organization for Rare Disorders - Focal Dermal Hypoplasia
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
