Nagayama spot are seen in:
b. Roseola infantum(Ref: Nelson 20/e p 1594-1596)Ulcers at uvulopalatoglossal junction (Nagayama spots) are commonly reported in infants with roseola infantum. High fever is the most consistent finding associated with primary HHV-6B infection.
Measles
Roseola infantum
Mumps
Rubella
General Considerations - Infectious Diseases