"Poverty-stricken kids" is a more theatrical phrase that could replace "poor boy" in a written piece, while "underprivileged youth" could be used in a formal context. "Deprived child" can also be used to imply the lack of basic necessities such as food, shelter, and clothing. "Disadvantaged kid" is another synonym, which highlights the unequal opportunities that some children face due to socioeconomic circumstances. "Indigent juvenile" can be used to describe the financial situation of the child. "Needy youngster" is also a viable alternative to "poor boy," which accurately captures the idea of an individual who requires aid and assistance.