Relapsing linear acantholytic dermatosis is a cutaneous condition characterized by relapsing linear erosions and crusting, histologically identical to Hailey–Hailey disease. : 849  It is not to be confused with transient acantholytic dermatosis. See also
Linear porokeratosis
List of cutaneous conditions


== References ==
Diagnosis
Prenatal diagnosis
PKS is commonly diagnosed by detecting its causative sSMC as defined by identifying the overexpression of its genetic material. This method has detected the sSMC and therefore diagnosed a fetus as having PKS based on genomic analyses of fetal skin fibroblasts, placenta chorionic villi, cells isolated from the amniotic fluid, fibroblasts isolated from the fetuss umbilical cord, and cells isolated from the fetuss umbilical cord blood. PKS can also be diagnose using fetal ultasound imaging methods. Ultrasound imaging in PKS commonly find fetuses that are too large for their gestational age, contain polyhydramnios (excess amniotic fluid in their amniotic sacs), and have rhizomelic limbs (shortening of the proximal part of the limbs). Less commonly, the imaging evidences diaphragmatic hernias and/or various other major PKS structural malformations. In most cases, however, the ultrasound findings are not diagnostic of PKS. Furthermore, ultrasound diagnoses is best applied in the second or third pregnancy trimester when structural anomalies are more clearly defined and detectable.Because the prenatal diagnosis of PKS using the methods just cited is difficult, often indecisive, and/or best employed later in a womans pregnancy, prenatal cell-free DNA screening (cfDNA screening), also known as noninvasive prenatal screening, has been used to diagnose PKS. This method can diagnose PKS in 10 week and older fetuses. In cfDNA screening, DNA from a mothers blood is extracted and screened for the presence of specific chromosome abnormalities such as those associated with the Down syndrome, Patau syndrome (also termed trisomy 13), and Edwards syndrome (also termed trisomy 18).