Genetic skin disorders are inherited conditions that affect the skin. The most common is ichthyosis vulgaris, a form of dry, thick, scaly skin. Inherited skin conditions are diagnosed and managed at Coastal Dermatology + Aesthetics in San Luis Obispo, with referral where a condition needs a specialist center.
Inherited, common, and usually mistaken for ordinary dry skin
Ichthyosis is a group of skin diseases that causes extremely dry, thick and scaly skin, and about 95% of people who develop ichthyosis have the same type: ichthyosis vulgaris. [1] Children usually develop it by inheriting a gene from one or both parents. [1] It is not contagious. [1]
The reason it goes unnamed for years is that it looks like ordinary dryness, and it responds partially to ordinary moisturizer, which is enough to keep anyone from asking the question. The scale tends to be worse in dry, cold months and better in humid weather, which reinforces the impression that it is a seasonal nuisance rather than a diagnosis.
The genetics are unusually well understood for a skin condition, and they explain a lot. The gene involved makes a protein that plays an important role in the skin’s barrier. [3] More than 40 changes in that gene are known to cause ichthyosis vulgaris. [3] How many copies are affected is what determines severity. With one altered copy people are typically mildly affected, may have symptoms only seasonally, and may never have obvious skin problems at all. With two altered copies symptoms are more severe and can be present year-round. [3]
The same gene sits behind a lot of eczema, which is why atopic dermatitis, better known as eczema turns up in the same people and the same families. Between 20% and 30% of people with atopic dermatitis carry a change in this gene, against 8% to 10% of people without it. [3]
Other inherited conditions affect the skin, and their range is wide. Epidermolysis bullosa is a group of rare diseases that cause the skin to blister easily, [4] and it is covered below, alongside what gets managed here and what gets referred. Some pigmented birthmarks, including café au lait spots, are among the marks that do not fade with time. [7]
The share of people with ichthyosis who have ichthyosis vulgaris, the mild and common form. [1] Which means the version most people have is the one with a straightforward management routine.
How these are inherited
A gene passed down
Children usually develop ichthyosis vulgaris by inheriting the gene from one or both parents. [1] Most inherited skin conditions work the same way: the difference is in which gene and how many copies. Epidermolysis bullosa is caused by gene mutations in every type but one. [5]
One copy or two
With ichthyosis vulgaris the count matters. One altered copy typically produces mild, sometimes seasonal, sometimes barely noticeable dryness. Two altered copies produce more severe symptoms that can be present all year. [3] That is why the same condition in the same family can look like nothing in one person and like a real problem in another.
Which is also why a family history is worth mentioning
The condition is inherited, so somebody else in the family usually has it, often without knowing what it is called. Bringing that up at an appointment is genuinely useful information, and it frequently produces the diagnosis faster than the examination alone.
The window for applying moisturizer after bathing. Applying it to damp skin within two minutes of getting out is what makes the routine work. [2] Soaking first helps hydrate skin and soften scale. [2]
What actually helps ichthyosis vulgaris
There is no cure for inherited ichthyosis vulgaris, and treatment focuses on reducing the scale and the dryness. [2] The routine below is unglamorous and it is the whole of it, and the specifics are what separate it from generic dry-skin advice.
| Step | What to do | Why |
|---|---|---|
| Soak | Bathe or soak rather than showering quickly | Soaking hydrates skin and softens the scale [2] |
| Apply on damp skin | Moisturize within two minutes of getting out, while skin is still damp | The window is what traps the water in [2] |
| Use an active ingredient | Look for urea, alpha hydroxy acid or lactic acid in the moisturizer | These are what work on scale, rather than a plain emollient [2] |
| Repeat, indefinitely | Daily, year round, heavier in dry months | The condition is inherited, so the routine is maintenance rather than a course |
Diagnosis is usually straightforward. A dermatologist can often diagnose ichthyosis vulgaris by looking at the skin. [2] What the appointment adds is the name, the correct products, and the connection to eczema if it is present, which changes how both are handled.
The eczema connection is the part worth taking away. Between 20% and 30% of people with atopic dermatitis carry a change in the same gene, against 8% to 10% of people without it. [3] If you have had lifelong dry, scaly skin and you also have eczema, those are not two coincidences. Treating the barrier properly helps both.
Where scaling is severe, does not respond to this routine, or is accompanied by other findings, the diagnosis may be a different form of ichthyosis, and that is worth establishing rather than assuming.
What is managed here, and what is referred
Inherited skin conditions run from very common and easily managed to very rare and genuinely complex. Being clear about which is which is more useful than implying that one practice covers all of it.
| Condition | Where it is handled |
|---|---|
| Ichthyosis vulgaris | Diagnosed and managed here [1] [2] |
| Dry, scaly skin alongside eczema | Managed here, and the two are treated together [3] |
| Café au lait spots and other pigmented birthmarks that do not fade | Examined here [7] |
| Rarer forms of ichthyosis | Diagnosed here, with onward referral where genetic evaluation is warranted |
| Epidermolysis bullosa | Care belongs with a specialist center. Evaluation and coordination here, referral onward [4] [6] |
| Inherited conditions with findings beyond the skin | Co-managed, with the skin part handled here |
On epidermolysis bullosa specifically. It is a group of rare diseases that cause the skin to blister easily, [4] and it covers a wide range: some children have a mild form that mainly calls for precautions against injury, and others live with a severe form that needs specialist care throughout life. [4] Blistering and skin fragility are usually noticeable at birth or shortly after, [5] and it is estimated that between 25,000 and 50,000 people in the United States have it. [5] In the more severe types, skin cancer surveillance is part of ongoing specialist care. [6] The university centers in California run dedicated programs for it, and the right move for a family is a referral there rather than a local page claiming otherwise.
The staff is terrific, front to back. Thank you, Dr. Kilcline, for the great work today.
The Coastal difference
A name changes what you buy and what you do
Most people who have ichthyosis vulgaris have never been told they have it. They have been told they have dry skin, and they have bought a great deal of moisturizer that was never formulated for scale. The practical value of the appointment is small and real: a name, the right active ingredients, and a routine with a two-minute window in it. [2]
The second thing an appointment produces is the connection. Where inherited dry skin and eczema occur together, they share a mechanism, and knowing that changes how both are managed rather than treating them as separate complaints in separate visits. [3] The same logic applies where a rash turns out to belong with psoriasis or with autoimmune skin conditions instead.
The third thing is honest scoping, which is the managed-or-referred table above. There is real value in a local practice saying plainly which inherited conditions it manages and which belong at a specialist center, because the alternative is a family spending months finding that out on their own.
What determines severity in ichthyosis vulgaris. One altered gene copy is typically mild and sometimes seasonal. Two produce symptoms that can be present year round. [3]
When to see a dermatologist
Book an appointment if:
- You have had dry, scaly skin for as long as you can remember, particularly on the shins and arms
- The scale is plate-like or fish-scale in pattern rather than simply rough
- Ordinary moisturizer helps a little and never quite resolves it
- Other people in your family have the same skin
- You have eczema alongside lifelong dryness
- A child has blistering or fragile skin from birth or shortly after [5]
- A birthmark has not faded and you would like it identified [7]
A dermatologist can often diagnose ichthyosis vulgaris by looking at the skin, [2] so this is usually a single appointment that produces a name and a plan rather than a diagnostic process.
Managing inherited dry skin
The routine
- Soak or bathe rather than showering quickly, because soaking hydrates skin and softens the scale [2]
- Moisturize within two minutes of getting out, on damp skin [2]
- Use a moisturizer containing urea, alpha hydroxy acid or lactic acid rather than a plain emollient [2]
- Expect to do it year round, and expect to do more of it in dry, cold months
- There is no cure for inherited ichthyosis vulgaris, and treatment reduces the scale and the dryness effectively [2]
Worth knowing
- Ichthyosis is not contagious [1]
- About 95% of ichthyosis is ichthyosis vulgaris, the mild and common form [1]
- It is inherited from one or both parents, and severity tracks with how many gene copies are affected [1] [3]
- Between 20% and 30% of people with atopic dermatitis carry a change in the same gene [3]
- Some inherited marks, including café au lait spots, do not fade with time [7]
- Where a condition belongs with a specialist center, a referral is part of what an appointment produces
Treatments we offer
Diagnosis, a management plan built around the specific condition, and referral where a condition belongs with a specialist center. Pick a treatment to see how it works.
What treatment costs
Diagnosis and management of an inherited skin condition are medical care rather than a cosmetic service, and are handled differently from the aesthetic treatments on this site. Our office will go through what applies to you when you book.
Prescription moisturizers and topical treatments are dispensed through a pharmacy and are billed separately from the visit.
The common one
Ichthyosis vulgaris. About 95% of people who develop ichthyosis have this type [1]
How it is inherited
From a gene inherited from one or both parents, and how many copies affects how mild it stays [1] [3]
The routine that works
Moisturizer applied to damp skin within two minutes of bathing, using urea, alpha hydroxy acid or lactic acid [2]
Why it runs with eczema
The same gene is involved in both, and it is the reason the two turn up in the same families [3]
Genetic skin disorder frequently asked questions
People with atopic dermatitis who carry a change in the same gene behind ichthyosis vulgaris, against 8% to 10% of people without it. [3] Which is why the two keep appearing together.
Offered at
Skin that has always been dry and scaly? Request an appointment
Fill out the form below, book online in Santa Maria (opens online scheduler), or give us a call. Cosmetic and aesthetic appointments need no referral. For medical dermatology, we are accepting new patients by referral from your primary care physician; send the referral across and then use the same form.
Sources and medical review
1. American Academy of Dermatology Association. “Ichthyosis vulgaris: Overview.” States that “ichthyosis is a group of skin diseases that causes extremely dry, thick, and scaly skin,” that “about 95% of people who develop ichthyosis get this type,” that “children usually develop it when they inherit a gene(s) for the disease from one or both parents,” and that “ichthyosis isn’t contagious, so you cannot catch it from someone.” https://www.aad.org/public/diseases/a-z/ichthyosis-vulgaris-overview · Medical Organization
2. American Academy of Dermatology Association. “Ichthyosis vulgaris: Diagnosis and treatment.” States that “a dermatologist can often diagnose ichthyosis vulgaris by looking at a patient’s skin,” advises to “apply moisturizer to damp skin within two minutes of bathing,” states that “your dermatologist may recommend a moisturizer that contains an active ingredient like urea, alpha hydroxyl acid, or lactic acid,” that “soaking helps hydrate your skin and soften the scale,” and that “there is no cure for inherited ichthyosis vulgaris. Treatment focuses on reducing the scale and dry skin.” https://www.aad.org/public/diseases/a-z/ichthyosis-vulgaris-treatment · Medical Organization
3. MedlinePlus Genetics, U.S. National Library of Medicine. “FLG gene.” States that “the FLG gene provides instructions for making a large protein called profilaggrin, which is found in cells that make up the outermost layer of skin (the epidermis),” that “filaggrin plays an important role in the skin’s barrier function,” that “more than 40 FLG gene mutations have been found to cause a relatively common skin disorder called ichthyosis vulgaris, which is characterized by dry, scaly skin,” that “typically, individuals with a mutation in one copy of the FLG gene are mildly affected; they may have symptoms only seasonally, or they may never have obvious skin problems,” that “individuals with two mutated copies of the gene have more severe symptoms that may be present year-round,” that “mutations in the FLG gene are strongly associated with a skin disorder called atopic dermatitis (also known as atopic eczema),” and that “twenty to 30 percent of people with atopic dermatitis have an FLG gene mutation compared with 8 to 10 percent of the general population without atopic dermatitis.” https://medlineplus.gov/genetics/gene/flg/ · Government Organization
4. American Academy of Dermatology Association. “Epidermolysis bullosa: Overview.” States that “epidermolysis bullosa (EB) is a group of rare diseases that cause the skin to blister easily,” that “epidermolysis bullosa simplex (EBS): This is the most common type,” that “Kindler syndrome: This is a very rare type of EB,” and that “some children have a mild disease that requires taking precautions to prevent injuries,” while at the other end of the spectrum EB can be severe and lifelong. https://www.aad.org/public/diseases/a-z/epidermolysis-bullosa-overview · Medical Organization
5. American Academy of Dermatology Association. “Epidermolysis bullosa: Causes.” States that “all but one type, epidermolysis bullosa acquisita (EBA), are caused by gene mutations,” that “it is estimated that between 25,000 and 50,000 people in the United States have EB,” and that “most types of EB begin in childhood. The fragile skin and blistering of EB are usually noticeable at birth or shortly thereafter.” https://www.aad.org/public/diseases/a-z/epidermolysis-bullosa-causes · Medical Organization
6. National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health. “Epidermolysis Bullosa.” Describes it as “a group of rare diseases that cause the skin to be fragile and to blister easily,” states that “most people who have epidermolysis bullosa inherit a mutated (changed) gene from their parents,” names the four groups as epidermolysis bullosa simplex, junctional epidermolysis bullosa, dystrophic epidermolysis bullosa and Kindler syndrome, states that “the symptoms of the disease usually begin at birth or during infancy and range from mild to severe,” and notes an elevated risk of skin cancer that warrants ongoing surveillance. https://www.niams.nih.gov/health-topics/epidermolysis-bullosa · Government Organization
7. American Academy of Dermatology Association. “Birthmarks: Diagnosis and treatment.” States that “birthmarks that don’t fade with time include café au lait spots, moles, and port-wine stains,” and that a dermatologist should examine a birthmark as soon as it is noticed. https://www.aad.org/public/diseases/a-z/birthmarks-treatment · Medical Organization
8. Foundation for Ichthyosis and Related Skin Types. “Eczema and Ichthyosis.” States that mutations in the filaggrin gene “confer a substantial risk of atopic dermatitis,” and that “the gene involved codes for the precursor form of filaggrin, a protein involved in the final stages of formation of the barrier of the epidermis.” https://www.firstskinfoundation.org/eczema-and-ichthyosis · Nonprofit Organization
Content on this page is for educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Inherited skin conditions vary widely in severity and in what they involve beyond the skin, and the descriptions here are general rather than specific to any individual. Genetic testing and genetic counseling are separate services and are arranged by referral where they are appropriate. Several inherited skin conditions are managed by specialist centers, and referral is part of what an evaluation produces. Individual results may vary.