Figure 2. Tanner Staging for pubertal development in boys. In boys, genital development is rated from 1 (preadolescent) to 5 (adult); stage 2 marks the onset of pubertal development and is characterized by an enlargement of the scrotum and testis and by a change in the texture and a reddening of the scrotal skin. Pubic hair stages are rated from 1 (preadolescent, no pubic hair) to 5 (adult), and stage 2 marks the onset of pubic hair development. Although pubic hair and genital or breast development are represented as synchronous in the illustration, they do not necessarily track together and should be scored separately. In normal boys, stage 2 pubic hair develops at an average of 12 to 20 months after stage 2 genital development. Figure 2 Adapted with permission from Carel JC, Léger J. Clinical practice. Precocious puberty. N Engl J Med. 2008;358(22):2367 and Klein DA, Emerick JE, Sylvester JE, Vogt KS. Disorders of Puberty: An Approach to Diagnosis and Management. Am Fam Physician. 2017 Nov 1;96(9):590-599. PMID: 29094880