Work on the building began in 1634 and was only completed in 1706 with the onion-shaped bell tower.
In 1748, the side chapel of San Gaetano was opened, in 1756 the high altar was installed thanks to a generous bequest, and in 1773 Pietro Scalvini painted the frescoes in the dome celebrating the glory of San Carlo with annexed cardinal virtues.
The façade, with a triangular pediment, has a medallion with the motto “Humiltas” and the Borromeo coat of arms, but it is the side entrance that stands out with its portico and Corinthian columns. The interior, almost as if to provide previous antiquities, contains the altar of the Body of Christ dating back to 1539, possibly from the parish church, and the altarpiece by Francesco Paglia, enclosed in a rich soasa dating back to the late seventeenth century.
Pietro Scalvini also created two medallions in the side chapels: they depict San Carlo caring for the plague-stricken and San Carlo distributing his wealth to the poor. A jubilation of gratitude to the saint who had severely criticised the faithful during the visits made in the Anno Domini 1580.