At or soon after birth most infants with Netherton syndrome look 'scalded'. The skin is 'leaky' causing infants to lose heat, water and proteins, all of which are necessary for normal growth and development. For the most severely affected infants, the prognosis of Netherton syndrome is poor and, despite improved management of these babies, there remains a risk that the baby may not survive beyond the first six months of life. Most suffer from severe failure to thrive in the first year. The defective skin makes these babies at a higher risk of infection.
Later in childhood, some develop a distinctive circular scaling on the skin known as ichthyosis linearis circumflexa. The skin condition tends to go through bouts of flaring and may be itchy, sensitive or raw and often thickened at the joints. Individuals may become distressed if the skin, especially the face, is constantly red and peeling. Between episodes, the skin may appear relatively normal. In Netherton syndrome, the hair breaks easily making it look spiky on the scalp, but microscopic hair changes are also seen on the eyelashes, eyebrows and body hair. Individuals with Netherton syndrome have a higher risk of allergies and anaphylaxis. Some individuals are allergic to foods such as fish and nuts or are prone to hay fever, asthma and eczema-like rashes. Children with Netherton syndrome have high levels of IgE (an allergy antibody) in their blood and suffer attacks of agioedema (allergy-induced swelling). Individuals with Netherton syndrome are usually shorter than average and may have difficulty gaining weight. Gastrointestinal problems, such as diarrhoea, occur often, especially in early infancy.