What is Epidermolytic Hyperkeratosis?
Epidermolytic hyperkeratosis is a rare skin condition linked to inherited traits that results from changes in specific skin proteins called keratins 1 and 10. This was initially known as bullous congenital ichthyosiform erythroderma due to its key features. These include red skin inflammation, blistering, and loss of skin that’s present from birth, followed by thickening of the skin. Sometimes, this condition can also affect palms and soles. It’s easy to recognize epidermolytic hyperkeratosis among other inborn skin disorders due to its one-of-a-kind changes that can be seen under a microscope. In more modern studies, the term ‘Epidermolytic hyperkeratosis’ is used to describe the changes in the skin, while the disease itself is referred to as epidermolytic ichthyosis.
What Causes Epidermolytic Hyperkeratosis?
Epidermolytic hyperkeratosis is a skin condition that is mainly caused by changes in the genes that make two proteins, called keratin 1 and keratin 10. These changes are called point or missense mutations. Most cases of this skin condition are passed down from parent to child in a way that geneticists call “autosomal dominant” inheritance.
There’s a severe form of the condition that shows up in some families. This is caused by what are called autosomal recessive loss-of-function mutations in the gene for keratin 10.
Interestingly, about half of the cases of this condition are caused by mutations that happen randomly, and not inherited from parents.
Certain mutations in keratin 1 are linked with a form of the disease that also causes severe hard skin on the hands and feet, a condition known as palmoplantar keratoderma. Mutations in keratin 10, however, lead to a form of the disease that doesn’t involve this skin hardening on palms and soles.
Epidermolytic hyperkeratosis can affect a child if a parent has a particular skin condition called “epidermal nevi”, due to what is known as genetic mosaicism. This allows for some skin cells to have different genes than others. This Yields two forms of the illness called ichthyosis hystrix or linear epidermolytic hyperkeratosis. These forms are caused by mutations in keratin 1 and keratin 10 genes that occur after conception. If these changed genes are in cells that eventually produce eggs or sperm, they can be passed down to a child who will then have the typical symptoms of epidermolytic hyperkeratosis. It’s worth noting that currently, epidermolytic hyperkeratosis is the only known skin disease that shows genetic mosaicism.
Risk Factors and Frequency for Epidermolytic Hyperkeratosis
Epidermolytic hyperkeratosis is a skin condition that affects about 1 in every 200,000 to 300,000 infants. This disorder is mainly hereditary, meaning it can be passed down from parents to their children, and it affects both genders equally.
Signs and Symptoms of Epidermolytic Hyperkeratosis
Epidermolytic hyperkeratosis is a skin condition that becomes visible at birth. It initially presents as widespread redness of the skin. The skin also becomes fragile, which can lead to blisters, scrapes, and large areas of skin loss, even from minor injuries. However, after several months, the redness and blistering tend to decrease, and a severe form of skin thickening or “hyperkeratosis” develops.
Sometimes, these skin changes continue and cause patients to periodically lose large flakes of the top layer of skin. The thickened skin often looks like crinkled card paper on bending areas or resembles a cobblestone pattern on the extending surfaces of the joints. In some cases, the scalp and neck can be heavily involved, which can cause hair loss. Another feature of this condition may include a particularly bad-smelling odor from the skin, similar to rotten eggs, due to the buildup of bacteria. There are also other symptoms that can occur, such as:
- Dry skin
- Itching
- Painful skin cracks
- Reduced sweating
- Limited movement of the joints
In addition to this, scientists have classified Epidermolytic hyperkeratosis into different types based on the combination of symptoms and their appearance. One way of classifying this condition is whether there are changes in palms and soles or not. Each of these classifications has further types based on the severity and distribution of redness, blistering, scaling, and trunk involvement. Some types may also present with restrictions in finger movements due to skin changes affecting the palms and soles. Other types include unilateral or bilateral stripes of skin thickening or features like protruding spines have been termed “ichthyosis hystrix.”
Testing for Epidermolytic Hyperkeratosis
Diagnosis of a condition usually relies on a combination of factors such as patient symptoms, physical findings, and laboratory tests. This rule applies to a condition called epidermolytic hyperkeratosis, a genetic skin disorder.
The best way to diagnose this condition today is through genetic testing, particularly looking for defects in proteins called keratins. This testing approach is even usable before a child is born (that’s “prenatal screening”).
Prenatal diagnosis can be done using techniques like chorionic villus sampling and amniocentesis, which involve testing samples taken from the womb. Fetoscopy, a procedure which involves using a small camera to see and take a sample of the baby’s skin, can also help identify this condition before birth.
However, it’s important to note that these tests are not perfect. They may miss some cases (low sensitivity) or may not identify every potential genetic cause (genetic heterogeneity).
Other techniques being explored for diagnosing include Raman spectroscopy and optical coherence tomography. These optical and spectroscopic techniques are special ways of “seeing” skin changes without having to remove skin for testing. This could potentially help in the diagnosis of not just conditions like epidermolytic hyperkeratosis, but also nonmelanoma skin cancers.
Treatment Options for Epidermolytic Hyperkeratosis
If you’re dealing with a skin condition that causes hard, rough patches of skin (a condition called hyperkeratosis), the various treatments available will depend on several factors. These include how old you are and the severity of your symptoms. For babies, the focus is usually on keeping them in a controlled environment like the intensive care unit where doctors can carefully manage any potential problems. These problems could include dehydration, imbalances in electrolyte levels (chemicals in your blood and other body fluids that carry an electric charge), and skin infections.
When it comes to children and adults, the main goal of treatment is to reduce the thickening and roughness of the skin. Creams and lotions, sometimes with added ingredients to soften the skin or encourage the shedding of dead skin cells, can help manage hyperkeratosis. However, these products might not be suitable for everyone as they can sometimes cause a burning or stinging sensation. It’s also important to avoid excessive use of products containing salicylic acid, as too much can lead to a condition known as “salicylism” where the acid builds up in your body.
Other options include use of topical retinoids, N-acetylcysteine, liarozole, and calcipotriol. These treatments have been found to help improve skin cell function and reduce excessive skin cell growth, but they might irritate the skin for some people. In severe cases, oral retinoids (a type of vitamin A) can significantly improve the condition of the skin, but they may also make your skin more prone to blistering. Because of this, doctors usually start you off with a low dose and gradually increase the dose as needed, while closely monitoring your response to the treatment.
Interestingly, how well these treatments work can depend on what specific type of hyperkeratosis you have. For example, if your condition is due to a specific mutation in a gene called keratin 10, you might respond better to retinoids than if you have a mutation in a different gene called keratin 1.
Finally, measures to reduce bacterial skin infections can also be helpful. These can include antibacterial soaps, preparations containing an antiseptic called chlorhexidine, and baths with a weak solution of sodium hypochlorite (basically a type of bleach). If a skin infection does occur, you might need to use antibiotics, either applied directly to the skin or taken by mouth.
What else can Epidermolytic Hyperkeratosis be?
The diagnosis of a skin condition known as epidermolytic hyperkeratosis can be tricky because it can be easily confused with other conditions that cause similar symptoms such as skin redness, blisters, or peeling, especially in children.
These conditions can be divided into three major groups:
- Other types of inborn dry and rough skin conditions (Ichthyoses):
- Superficial epidermolytic ichthyosis
- Lamellar ichthyosis
- Congenital ichthyosiform erythroderma
- Conditions that cause blistering and skin erosion during childhood:
- Epidermolysis bullosa
- Staphylococcal scalded skin syndrome
- Bullous impetigo
- Herpes simplex
- Congenital erosive and vesicular dermatosis
- Autoimmune blistering diseases
- Genetic skin diseases (Genodermatoses):
- Sjogren-Larsson syndrome
- Neutral lipid storage disease
- Trichothiodystrophy
- Netherton syndrome
- Steroid sulfatase deficiency
- Peeling skin syndromes
- Conradi-Hunermann-Happle syndrome
- CHILD syndrome
- KID syndrome
What to expect with Epidermolytic Hyperkeratosis
The impact of a skin condition named epidermolytic hyperkeratosis varies from person to person. Newborns with this condition face a higher chance of serious health problems like infection (sepsis), extreme thirst (dehydration), and even death. Since it’s quite a rare condition, we don’t have clear statistics on how often it leads to death.
For those who make it through the newborn phase, the condition doesn’t just go away. They can experience episodes of skin blistering and infections at different times throughout their lives. These skin problems can cause significant changes in physical appearance and unpleasant body smells, leading to serious psychological and social distress.
Possible Complications When Diagnosed with Epidermolytic Hyperkeratosis
Babies born with a condition known as epidermolytic hyperkeratosis are at a heightened risk of getting dehydrated, having electrolyte imbalances and suffering from sepsis. These issues arise from increased loss of water through the skin and ineffective skin barriers. If these complications are not treated promptly and correctly, they can be life-threatening. Additionally, if this condition severely impacts the palms of the hands and soles of the feet, it can cause the contraction of the fingers or toes. The result could be negatively affected movements, walking, and posture.
What could happen:
- Dehydration
- Electrolyte imbalances
- Sepsis
- Severe impact on palms and feet
- Contraction of fingers or toes
- Difficulty in joint movements
- Alteration in walking
- Problems with posture
Preventing Epidermolytic Hyperkeratosis
People who are living with a skin condition called epidermolytic hyperkeratosis often have skin that is more fragile than usual. This means their skin can easily get damaged, so it is crucial for them to learn how to lower chances of hurting their skin. One way to do this is by choosing to wear clothes that fit comfortably and are not too tight, and also making sure their shoes fit them properly.
