IPA: /ˌskɑːr.ləˈtiː.nəl/
KK: /ˈskɑːrlətɪnəl/
Related to a type of illness known as scarlet fever, which is characterized by a red rash and fever.
The doctor diagnosed the child with a scarlatinal infection after observing the rash.
Scarlatinal is derived from "scarlatina" (from Latin *scarlatina*, meaning scarlet fever) and the suffix "-al" (meaning pertaining to). The term "scarlatinal" refers to something that is related to or characteristic of scarlet fever.
Think of 'scarlatina' which refers to scarlet fever, and the '-al' indicates that it pertains to that condition.