Classically trained as an actress and violinist, Erikka launched her career as an original company member of the 8 Tony Award winning musical Once. She joined the production during it's first staged workshop at the American Repertory Theater, where she was studying for her MFA. Upon graduation, Erikka was officially cast as the Ex-Girlfriend and understudy for the leading role of Girl in the musical's Off-Broadway run at the New York Theater Workshop. The production seamlessly transferred to Broadway, garnering the Drama League Award for Distinguished Production of a Musical, 11 Tony Award nominations, and the 2013 Grammy Award for Best Musical Theater album, among numerous other awards and nominations. Erikka appeared in over 1,100 performances on Broadway in her role as Ex-Girlfriend, with additional performances as Girl and Reza.

Erikka holds an MFA from the American Repertory Theater/Moscow Art Theater Institute for Advanced Theater Training at Harvard University. Between 2 years of study in the States, and a 3 month intensive at the Moscow Art Theater School, Erikka studied under Scott Zigler, Andrei Droznin, Janos Szasz, David Hammond, Marcus Stern, Tommy Derrah, and Nancy Houfek in a eclectic collection of techniques and disciplines. Erikka also graduated summa cum laude from Temple University with a BA in theater.