In 2009 the term porokeratotic anexial ostial nevus was proposed to comprehend porokeratotic eccrine and hair follicle nevus and a related and more common process without follicular involvement: porokeratotic eccrine ostial and dermal duct nevus Recent findings suggest that both entities may be produced by a mutation in GJB2 gene, which is associated to KID syndrome.
Because histopathologic examination of two independent biopsies did not reveal porokeratotic eccrine ostial and dermal duct nevus (PEODDN), previously reported to result from somatic mutations in GJB2, it appears that mutations in this gene can cause nevoid spiny hyperkeratosis in the context of PEODDN or as an isolated finding.