Netherton syndrome

Netherton syndrome is a severe, autosomal recessive form of ichthyosis associated with mutations in the SPINK5 gene. It is named after E.W. Netherton.

Characteristics
Most babies who have it are "scalded-looking" at birth and are very slow to gain weight all through their life but especially in the first year. As a result they may well be kept in hospital for a few weeks or even months. The cracking/scaling of their skin causes them to lose water, heat and proteins and so care in incubators of these babies is essential along with extra fluids to compensate.

Individuals with Netherton's Syndrome also tend to have fragile and spiky hair, medically called trichorrhexis invaginata, which often grows very slowly. All body hair is affected by this (including eyebrows/eyelashes etc.). Microscopic examination of the hairs will reveal bamboo-like growths on the shaft of the hair. This will clinch the diagnosis if a physician is unsure and these swellings are also the reason for the brittleness of the hair. However, the absence of bamboo hair does not rule out the diagnosis - trichorrhexis invaginata sometimes does not show up until 6 months of age. Trichoscopy may be used to facilitate the diagnosis.

Allergies to nuts and fish are also common amongst affected people but they are not always present in every case.

Affected people are usually lighter and shorter than "normal" and may not do very well in sporting activities.

The usual cutaneous manifestation of Netherton syndrome is ichthyosis linearis circumflexa.

Cause and Genetics
Netherton syndrome is an autosomal recessive disorder associated with mutations in the SPINK5 gene, which encodes the serine protease inhibitor lympho-epithelial Kazal-type-related inhibitor (LEKTI). These mutations result in a dysfunctional protein that is unable to inhibit the serine proteases of the skin involved in epidermal remodelling and desquamation.

Treatment
There is no known cure at the moment but there are several things that can be done to relieve the symptoms. moisturising products are very helpful to minimise the scaling/cracking and anti-infective treatments are useful when appropriate because the skin is very susceptible to infection. Extra protein in the diet during childhood is also beneficial to replace that which is lost through the previously mentioned "leaky" skin.

Steroid and retinoid products have been proven ineffective against Netherton syndrome and may in fact make things worse for the affected individual.