Histologic examination revealed parakeratosis with psoriasiform epidermal hyperplasia, focal absence of the granular layer, and intracorneal as well as intraepidermal accumulations of neutrophils (Figure 3). Analysis of the hair shaft demonstrated characteristic "bamboo hairs" (trichorrhexis invaginata) (Figure 4). Genetic analysis of lymphocytic DNA from a peripheral blood sample confirmed the clinicopathologic diagnosis of Netherton syndrome by revealing 2 distinct mutations in the SPINK5 gene. The first mutation concerned exon 26 (2468insA), and the second was found in exon 16, generating an alternative splice site.
Generalized Exfoliative Erythroderma Since Birth—Diagnosis. Arch Dermatol. 2004;140(10):1275-1280. doi:10.1001/archderm.140.10.1275-b