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Lamellar ichthyosis
This condition results from faulty skin barrier function, leading to thickened, fish-like scales. It is present from birth and affects individuals across all ethnicities, requiring lifelong dermatological care within the NHS.
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Overview
Lamellar ichthyosis is a rare inherited skin disorder that affects the outermost layer of the skin, known as the epidermis. Individuals with this condition typically present at birth with a shiny, tight membrane called a collodion membrane, which sheds within the first few weeks of life [PMID:30080649]. Once the membrane sheds, the characteristic widespread scaling becomes apparent. The skin appears dry, red, and covered in dark, plate-like scales that are often more prominent on the trunk and limbs.
This condition is part of a group of genetic disorders called ichthyoses, which are characterised by abnormal skin scaling. Lamellar ichthyosis can impact daily life significantly, affecting comfort, appearance, and skin health. It requires ongoing medical management to help control symptoms and prevent complications.
Symptoms & clinical features
The primary symptom of lamellar ichthyosis is the presence of prominent, dark, plate-like scales covering most of the body. These scales can be shed and regrow, leading to persistent dryness and a feeling of tightness in the skin. The eyelids may be everted (turned outwards), a condition known as ectropion, which can lead to eye irritation and dryness. Hair can also be affected, sometimes appearing sparse or coarse, and the scalp may have thick scales.
Other symptoms often include thickened nails, and a reduced ability to sweat, which can make it difficult for the body to regulate its temperature, especially in warm environments. This can lead to overheating. Deep fissures or cracks in the skin, particularly around joints, can be painful and may increase the risk of skin infections. The palms of the hands and soles of the feet may also be thickened and dry [PMID:30080649].
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Affected organs
The skin is the primary organ affected by lamellar ichthyosis. The condition impairs the skin's barrier function, which is crucial for protecting the body from external factors and maintaining hydration. This widespread skin involvement can secondarily affect other systems. For example, severe ectropion can impact the eyes, potentially leading to corneal damage if not managed. The inability to sweat properly can affect the body's internal temperature regulation system. Hair follicles and nails, which are skin appendages, are also frequently involved.
Risks & severity
Lamellar ichthyosis presents with a spectrum of severity, though it is generally considered a severe form of ichthyosis. Complications can arise from the impaired skin barrier and chronic dryness. These include frequent skin infections due to cracks in the skin, heat intolerance from reduced sweating, and visual problems if ectropion is severe and leads to corneal exposure [PMID:34739506]. There is also a potential psychological impact due to the visible nature of the condition.
The condition is present from birth, and symptoms are lifelong. While the collodion membrane sheds within weeks, the scaling and other skin issues persist throughout an individual's life. Exact prevalence in the UK is not well established, but globally it is estimated to affect around 1 in 200,000 people.
Genetic causes
Lamellar ichthyosis is typically caused by genetic changes in the TGM1 gene. This gene provides instructions for making an enzyme called transglutaminase 1. This enzyme plays a vital role in the formation of the skin's outer layer (epidermis) and its barrier function. Specifically, transglutaminase 1 is crucial for cross-linking proteins to form the cornified cell envelope, a robust structure that helps protect the skin.
Pathogenic variants in the TGM1 gene lead to a faulty or absent transglutaminase 1 enzyme. Without a functional enzyme, the cornified cell envelope cannot form correctly, resulting in a defective skin barrier. This defect leads to the characteristic excessive scaling and impaired skin protection seen in lamellar ichthyosis [PMID:25700770]. While TGM1 is the most common gene involved, changes in other genes can also cause similar conditions, though these are rarer.
- TGM1 transglutaminase 1
Inheritance pattern
Lamellar ichthyosis is inherited in an autosomal recessive pattern. This means that a person must inherit two altered copies of the causative gene - one from each parent - to develop the condition. Individuals who have only one altered copy of the gene are called carriers. Carriers typically do not show symptoms of lamellar ichthyosis because their single working copy of the gene is sufficient to produce enough functional protein.
If both parents are carriers, there is a 1 in 4 (25%) chance with each pregnancy that their child will inherit two altered copies of the gene and therefore develop lamellar ichthyosis. There is a 2 in 4 (50%) chance that their child will be a carrier, and a 1 in 4 (25%) chance that their child will inherit two normal copies of the gene and neither have the condition nor be a carrier. Family members with a diagnosis of lamellar ichthyosis may be referred to a clinical genetics service for genetic counselling to understand these inheritance risks.
When both parents are carriers, each child has a 25% chance of being affected, 50% of being a carrier, and 25% of being unaffected.
Diagnosis & testing
Diagnosis of lamellar ichthyosis typically begins with a clinical examination by a dermatologist, based on the characteristic skin features present from birth. A skin biopsy, where a small tissue sample is taken for microscopic examination, can help confirm the diagnosis and distinguish it from other forms of ichthyosis.
Genetic testing is the definitive method to confirm lamellar ichthyosis and identify the specific gene changes responsible. This usually involves a blood test. In the UK, genetic testing for inherited ichthyosis, including lamellar ichthyosis, can be accessed via the NHS Genomic Medicine Service (GMS) pathways. A referral to a clinical genetics service or specialist dermatologist is typically required to initiate these tests. The relevant NHS R-code for testing for ichthyosis is R110 Congenital ichthyosis.
Management & lifestyle
Management of lamellar ichthyosis focuses on symptom relief, improving skin barrier function, and preventing complications. Treatment is lifelong and typically involves regular application of emollients (moisturisers) and keratolytics (creams that help shed scales) to soften and remove scales, and to hydrate the skin. Your healthcare team, often a dermatologist, will advise on suitable products and their application.
Regular bathing, sometimes with special additives, can help in scale removal. In some cases, oral retinoids (medications derived from vitamin A) may be prescribed to reduce scaling, though these require careful monitoring due to potential side effects. Managing ectropion may involve lubricating eye drops and, in some cases, surgical correction. Avoiding overheating is also important due to impaired sweating. Genetic counsellors can provide support and information about the condition's inheritance and implications for family planning.
UK care pathway
In the UK, individuals suspected of having a genetic skin condition like lamellar ichthyosis will typically be referred by their GP or another specialist to a dermatologist. If a genetic cause is suspected, the patient may then be referred to a clinical genetics service. This service can arrange genetic testing through the NHS Genomic Medicine Service (GMS), using the relevant R-codes such as R110 for congenital ichthyosis. Genetic counsellors within these services provide essential support, explaining the inheritance patterns, potential implications for family members, and helping individuals and families cope with the diagnosis.
Frequently asked questions
Is lamellar ichthyosis contagious?
No, lamellar ichthyosis is a genetic condition, not an infection. It cannot be passed from person to person through contact.
Can diet affect lamellar ichthyosis?
While a balanced diet is good for general health, there is currently no strong evidence to suggest that specific dietary changes can cure or significantly alter the course of lamellar ichthyosis. Management primarily focuses on topical skin care and medical treatments.
What is a collodion membrane?
A collodion membrane is a shiny, tight, cellophane-like membrane that covers the skin of babies born with certain types of ichthyosis, including lamellar ichthyosis. It typically sheds within the first few weeks after birth.
Will my children inherit lamellar ichthyosis?
Lamellar ichthyosis is inherited in an autosomal recessive pattern. This means if you have the condition, all of your children will inherit one altered copy of the gene from you. If your partner is not a carrier, your children will be carriers but are unlikely to develop the condition. If your partner is also a carrier, there is a risk with each pregnancy that your children could inherit two altered copies and develop the condition. Genetic counselling can provide personalised information about these risks.
Are there new treatments for lamellar ichthyosis?
Research into genetic skin conditions is ongoing, and new treatments are continually being investigated. While current management focuses on symptom relief, advancements in gene therapy and other targeted treatments are areas of active study. You can discuss the latest research with your dermatologist or clinical genetics team.
References
- Wu YC, Yao Q. Lamellar Ichthyosis. JAMA dermatology. 2023. PMID: 36576743
- Hotz A, Kopp J, Bourrat E. Meta-Analysis of Mutations in ALOX12B or ALOXE3 Identified in a Large Cohort of 224 Patients. Genes. 2021. PMID: 33435499
- Du J, Ashley N, McCoy N. Pediatric Lamellar Ichthyosis. Paediatric anaesthesia. 2026. PMID: 41677380
- Francis JS. Genetic skin diseases. Current opinion in pediatrics. 1994. PMID: 7951667
- Guenther LC, Kunynetz R, Lynde CW. Acitretin Use in Dermatology. Journal of cutaneous medicine and surgery. 2017. PMID: 28952335
- Takeichi T, Akiyama M. Inherited ichthyosis: Non-syndromic forms. The Journal of dermatology. 2016. PMID: 26945532
- Trindade F, Fiadeiro T, Torrelo A. Bathing suit ichthyosis. European journal of dermatology : EJD. 2010. PMID: 20522418
- Thakur V, Malhotra P, Lad D. Ponatinib-induced lamellar ichthyosis-like eruption. International journal of dermatology. 2020. PMID: 32196645