The Harriet Lane Handbook may be singing a new tune, “When I’m 64,” but with expanded and updated chapters, the just-published latest edition of the manual is living up to its familiar reputation as the “pediatrician’s bible.”

“The Harriet Lane Handbook is one of the most, if not the most, essential guide books for pediatricians,” says Johns Hopkins co-chief pediatric resident Lauren Kahl, who, with co-chief pediatric resident Helen Hughes, oversaw development of the book by pediatric residents and their advisers, who played the role of chapter editors.

Conceived by its founding editors in 1953 as a pocket-sized yet comprehensive “pearl book” for residents of the Harriet Lane Home, the predecessor to the Johns Hopkins Children’s Center, the manual has grown in popularity nationally and internationally as the go-to clinical resource for clinicians who treat children. Its 20^th edition in 2014 was notable as the first digital version of the handbook. Highlights in this 21^st edition—the book is published every three years to reflect changes in practice—include expanded chapters covering adolescent medicine, dermatology, genetics, microbiology/infectious disease, procedures and an updated drug formulary. Accuracy of content, Hughes and Kahl stress, is the highest priority.

“There is so much useful information in the book, with references ranging from how long to keep sutures in to the best antibiotics for ear infections,” says Hughes. “It’s fun to read the handbook in-depth as an editor because you learn what a treasure trove of information it is.”

Hughes and Kahl note that Janet Serwint, pediatric residency program director, and associate residency program directors Jeffrey Fadrowski and Thuy Ngo were invaluable in producing the book.