Prevalence of and risk factors for nutritional deficiency and food allergy in a cohort of 21 patients with Netherton syndrome.

BACKGROUND: Netherton syndrome (NS; OMIM: 256500) is a rare autosomal recessively inherited disease due to SPINK5 mutations. Hair and inflammatory skin involvement are variable along with allergies. Morbidity and mortality are high, particularly in infancy. A detailed clinical analysis of a NS patient cohort should broaden the understanding of nutritional challenges and allergic comorbidities. METHODS: In this retrospective monocentric cohort study, medical and dietetic records of pediatric NS patients, presenting between 1999 and 2018, were reviewed. The severity of skin involvement was assessed according to the extent of the body surface area (BSA) affected by erythema. RESULTS: We identified 21 patients with NS (median age 11.6 years). Within the first 6 months of life, requirements for fluid and kcals/protein were high for all patients (average 228 ml/kg/day) and infants had an average of 1.9 feed changes (range 0-4) due to food intolerance. Clinical evidence for IgE-mediated food allergy was present in 84.2% (16/19 children, 2 no data) with a range of 1-12 food allergies per patient. In 75%, more than one food had to be avoided. Specific IgE levels were falsely positive in 38.3% and 8/18 patients (44.4%). One-third (5/15; 6 no data) of patients, all with severe disease, had anaphylactic reactions following ingestion of fish (n = 2), sesame (n = 1), cow's milk (n = 1), and both peanut and egg (n = 1). CONCLUSIONS: Our data emphasize feeding difficulties in children with NS and reveal an unexpectedly higher prevalence of food allergies that gives evidence to the importance of early coordinated multidisciplinary care for overcoming these challenges in NS.