SPINK5 and Alzheimer disease: In conclusion, although clinical, trichoscopical, and histopathological features represent useful tools for NS diagnosis, due to the possibility of misdiagnosis with a severe form of AD (especially in adults), we suggest performing SPINK5 genetic testing; searching for a c.1258A>G polymorphism (rs2303067), especially in doubtful cases, to ensure a correct diagnosis; and genetic counselling for the patients and their relatives.