Background: Comèl-Netherton syndrome (CN) is characterized by atopic-eczema-like skin abnormalities combined with linear ichthyotic lesions, hair shaft abnormalities and atopy with high IgE levels. Objective: Five children with CN are described. In 2 of the 3 CN patients still alive, analysis of cytokines regulating IgE synthesis was performed. Methods: In peripheral blood mononuclear cells and cultures of purified T cells, mRNA expression and protein production of interleukin 4 (IL-4), IL-13, IL-5 and interferon were analysed. The results were compared with the values in age-matched atopic dermatitis patients and healthy children. Results: The 5 CN patients showed striking differences in disease severity and evolution. Marked differences were found in several cytokines in the 2 analysed CN patients. Low percentages of natural killer cells were observed in both CN patients. Conclusion: The regulation of IgE production in patients with CN is varied and complex. The CN patients were heterogeneous in terms of Th2 skewing.