Netherton syndrome: symptoms, diagnosis and care

Netherton syndrome (NS) is a rare inherited disorder that affects the skin, hair and immune system. Contact, the UK charity for families with disabled children, describes it as affecting all the skin, causing it to be permanently red and scaly, with abnormal hair known as bamboo hair and a susceptibility to eczema and allergies.

The skin normally acts as a barrier, keeping heat, water and protein in and infection out. In Netherton syndrome this barrier is defective, and the Ichthyosis Support Group says the skin becomes leaky, leading to loss of heat, protein and moisture and a susceptibility to infection. The condition belongs to the wider ichthyosis group of conditions, which the NHS describes as rare skin conditions that cause dry, scaly skin.

At or soon after birth most infants with NS look scalded, according to Contact and the Ichthyosis Support Group. The skin is at its reddest in the first year of life. MedlinePlus adds that some babies are born with a tight, clear covering called a collodion membrane that is shed in the first weeks, and that newborns may become dehydrated and develop skin or whole-body infections (sepsis).

Failure to thrive is a key feature, especially in the first two years of life. As children get older the skin tends to improve, although some stay red all over while others develop circular patches of red scaly skin known as ichthyosis linearis circumflexa. The skin may be itchy, sensitive or raw, with bouts of flaring, and may be thickened at the joints.

• Fragile, spiky, dull or brittle hair (bamboo hair), which may also affect eyebrows and eyelashes and may not be noticeable in infancy.

• Allergies to foods such as nuts and fish, hay fever, asthma and eczema-like rashes, with high IgE levels.

• Short stature and difficulty gaining weight; diarrhoea is common in early infancy.

• Build-up of scales in the ears that can impair hearing if not cleared regularly.

• Difficulty regulating body temperature, tiredness and overheating with activity.

NS is caused by changes in the SPINK5 gene on chromosome 5, which means the LEKTI protein is missing or does not work, so skin proteins break down too quickly and the outer skin layer becomes thin and fragile. Loss of the protein also affects hair growth and the immune system, which explains the allergies.

It is autosomal recessive. Each parent of an affected child carries one altered copy of the gene but usually has no signs. The Ichthyosis Support Group explains that a child must have two altered copies for the condition to occur, so it usually appears unexpectedly in a family, and that genetic counselling is available, with referral to a clinical geneticist requested through a GP or consultant dermatologist. Contact says prenatal diagnosis is available using molecular genetic analysis.

Doctors look at the skin and the hair. Contact says the diagnosis is based on clinical features, a skin biopsy showing characteristic features, an antibody test on the skin sample showing absence of LEKTI, and molecular genetic studies on blood DNA confirming the genetic change. The Ichthyosis Support Group adds that cut hair under a microscope shows defects of the hair shaft, though this may not be reliable in early life because the changes may not have appeared yet.

Because red skin at birth can be a symptom of other forms of ichthyosis, severe eczema or immune deficiency, diagnosis may take months or years. A skin biopsy is usually done by a dermatologist, and blood is sent to a national reference laboratory to check the SPINK5 gene, according to the charity.

There is no specific cure. The Ichthyosis Support Group says continual care with moisturisers, anti-infection treatments and nutritional advice should help keep the skin as healthy as possible. Greasy moisturisers or ointments should be applied frequently, they should be perfume-free and additive-free, and soaking in a bath is more beneficial than a shower. The charity says steroid creams or retinoid medicines should be avoided as they do not tend to help and can even make the condition worse, and MedlinePlus notes that the skin is abnormally absorbent, which can lead to excessive blood levels of some topical medicines.

Other parts of care include antibiotics or antiseptics to protect against infection, regular ENT appointments for micro-suction to clear ear scales, dietitian advice for poor weight gain and multiple food allergies (with tube feeding in some babies), extra fluids to avoid dehydration, physiotherapy and support at school. Always check with a pharmacist, dermatology nurse or dermatologist before trying a new cream.

The first year is the critical period. Contact and the Ichthyosis Support Group both say some severely affected infants may not survive, while MedlinePlus says the health of older children and adults usually improves, although they often remain underweight and short. The skin tends to improve with age in most children but the underlying problem persists.

Researchers are exploring ways of replacing the missing protein, including topical products, gene therapy and stem cell approaches. The Ichthyosis Support Group describes this as early-stage. Ask your specialist team about clinical trials and the current state of research, as the information in older charity pages may be dated.

Babies and children with NS should be under specialist dermatology care. Seek urgent medical help for fever, lethargy, poor feeding, signs of dehydration or any rapid change in a baby with this condition, or for swelling of the lips, face or breathing difficulty after eating, which may be an allergic reaction. The Ichthyosis Support Group is the main UK source of information and support, and the NHS ichthyosis page is a starting point for general information.