Among girls: The first sign is the enlargement of breasts, which may be unilateral initially. Pubic hair, axillary hair and axillary odor also start appearing at the same time. Menarche is the latest event and occurs mostly 2-3 years after the onset of breast enlargement.

Among boys: The first signs of precocious puberty among boys are the testicular enlargement. After a year of testicular enlargement, there is the growth of the penis and scrotum. Pubertal growth spurt or accelerated linear growth is seen in the course of male puberty [6] [7].

• Precocious Puberty

  1–3 with implications for the definition of precocious puberty. [touchendocrinology.com]

  Heterosexual precocious puberty causes signs of masculine characteristics in girls and feminization in boys. Cerebral precocious puberty differs in cause but mimics true precocious puberty. [healthcentral.com]

  […] idiopathic precocious puberty isosexual precocious puberty male-limited precocious puberty peripheral precocious puberty General Discussion Precocious puberty means an abnormally early onset of puberty. [rarediseases.org]

  Classifications of Precocious Puberty Precocious puberty may be caused by a process occurring either centrally (gonadotropin-dependent precocious puberty, or GDPP) or peripherally (gonadotropin-independent precocious puberty, or GIPP). [ndnr.com]

  Most girls (95%) with precocious puberty have idiopathic true precocious puberty. Boys more commonly (>50%) have an identifiable etiology for precocious puberty. [academic.oup.com]

• Accelerated Growth

  A 7-year-old Indian girl presented with symptoms of excessive development of breasts, early menarche, growth of pubic hairs, accelerated growth and abdominal distension. On clinical examination, a large right abdominopelvic mass was palpable. [ncbi.nlm.nih.gov]

  Affected individuals may encounter psychological problems due to their accelerated growth and may feel alienated from their peers. They may exhibit increased aggressiveness and hyperactivity. [healthcentral.com]

  Early puberty accelerates growth. These children may initially be considerably taller than their peers. Because bone maturation is also accelerated, growth may be completed at an unusually early age, resulting in short stature. [emedicine.com]

  Precocious Puberty Precocious puberty means having signs of puberty (such as pubic hair or breast growth) at an age younger than normal. [childrensoncologygroup.org]

• Asymptomatic

  Pineal cysts are usually asymptomatic incidental findings, but have been associated with CPP. We present an interesting case of a patient with CPP and an associated pineal cyst. [ncbi.nlm.nih.gov]

  Suggestions are made as to how to approach the decision-making process with the parents regarding brain imaging in asymptomatic 6–8 year old girls with CPP. [ijpeonline.biomedcentral.com]

  Males with Paternally Inherited MKRN3 Mutations May Be Asymptomatic. J Pediatr. 2016 Sep 15. pii: S0022-3476(16)30848-4. doi: 10.1016/j.jpeds.2016.08.065. [ghr.nlm.nih.gov]

  Squares indicate male family members, circles female family members, black symbols clinically affected family members, symbols with black circles asymptomatic carriers, symbols with an X deceased family members, symbols with a question mark family members [doi.org]

• Goiter

  Thyroid gland was normal size and goiter was not noted. Her bone age was about 8 years. On abdominal sonography uterus and ovaries were normal. [ijp.mums.ac.ir]

• Deepening of Voice

  Boy Enlarged penis and testicles Facial hair Deepening of voice Girls Breasts Periods Boys and Girls Pubic and underarm hair Acne Mood swings Early growth spurt Most children do not need treatment for precocious puberty. [cincinnatichildrens.org]

  […] of voice, hirsutism Biochemical investigations ● Serum LH and FSH levels (baseline) ● GnRH (LHRH) stimulation test (LH and FSH) ● Estradiol/testosterone levels ● Adrenal steroids, e.g. 17 OH progesterone, dehydroepiandrosterone sulphate and androstenedione [obgyn.onlinelibrary.wiley.com]

• Overeating

  A rapid rate of linear growth (over 6 cm per year over the usual growth) and skeletal maturation (measured as an increased bone age on a hand x-ray) suggests either GDPP or GIPP specifically due to ovarian or testicular disease with high concentrations [ndnr.com]

  She is tall for her age and her mother reports noticeable breast development and pubic hair growth over the last six months. The girl’s height is between the 75th and 91st centiles. Her mother recalls that her own periods began at age 11. [bmj.com]

  However, across all groups there was change over time with a decrease in perceived physical competence (p < 0.001) and an increase in perceived maternal acceptance (p = 0.001). [ncbi.nlm.nih.gov]

  Neither of these girls had peak LH levels over 15 IU/L or peak LH-to-peak FSH ratios over 0.66, so by Palmert’s or our criteria would not have been treated. [academic.oup.com]

  Whether early puberty in boys is becoming more common over time, as is the case in girls, is unclear. [emedicine.com]

• Hypotension

  Symptoms are usually as a sequelae from adrenal insufficiency (because of 21-hydroxylase deficiency or 11-beta hydroxylase deficiency, the former being more common), which includes but is not limited to hypertension, hypotension, electrolyte abnormalities [en.wikipedia.org]

• No Pubic Hair

  Precocious puberty was identified by Tanner stage of breast, pubic hair and testicle development. A χ 2 test was performed to compare rates. [ncbi.nlm.nih.gov]

  Affected girls have premature development of their breasts and pubic hair, experience rapid growth, and may have irregular vaginal bleeding (due to the stimulatory effects of estrogen alone on the endometrium). [britannica.com]

  Graph represents the prevalence of pubic hair at Tanner stage 2 or greater by age and race. [emedicine.com]

  hair, but no BA advance or growth spurt; 4) breast development, growth spurt, and BA advance, but no pubic hair; 5) breast development and pubic hair and either growth spurt or BA advance; and 6) breast development and pubic hair and both growth spurt [academic.oup.com]

• Hirsutism

  Other clinical symptoms of hyperandrogenism, such as hirsutism, were not found in this population. [doi.org]

  ● Neurological examination ● Examination of eyes including visual fields and fundoscopy ● Skin lesions (e.g. café au lait spots) ● Abdominal examination ● Examination of external genitalia ● Signs of virilisation: clitoromegaly, deepening of voice, hirsutism [obgyn.onlinelibrary.wiley.com]

  J Pediatr 92:897, 1978 47 Salardi S, Orsini LF, Cacciari E, et al: Pelvic ultrasonography in girls with precocious puberty, congenital adrenal hyperplasia, obesity, or hirsutism. [glowm.com]

• Sweating

  This is often followed by the growth of pubic hair, body odor (from more active sweat glands), and acne (from more active oil glands). [babycenter.com]

  This summer I noticed that she was starting to sweat with "adult" body odour from her armpits. Tonight she asked me about a hair in her bottom, and showed me what looks like a pubic hair. [mumsnet.com]

• Flushing

  […] reproductive function seems to be unaffected.18 Pubertal manifestations generally reappear within months of GnRHa treatment being stopped, with a mean time to menarche of 16 months.19 Adverse effects The adverse effects of GnRHa include headaches, hot flushes [obgyn.onlinelibrary.wiley.com]

  Side effects of GnRH agonist treatment may include local reactions such as erythema, induration, and wheal and sterile abscess formation; negative effects on growth velocity; and transient headaches, hot flushes, and withdrawal bleeding. 60 Table 7. [glowm.com]

• Hypertrichosis

  Twenty two girls had some symptoms of hypertrichosis but none showed evidence of true hirsutism. Age at onset of Breast Stage 2 was younger than Lithuanian Standard 19 developed 15 years ago (11.5 years, range 9–16; p < 0.01). [doi.org]

• Meningism

  CAUSES Structural Head injury Infection of brain (Meningitis) Thyroid Primary sexual organs 8. In maximum no: of girls there is no proper reason mentioned about their precocious puberty and the etiology is mostly unknown. [slideshare.net]

  It is idiopathic or secondary to hypothalamic lesions such as tumors (hypothalamic hamartoma, glioma, astrocytoma), CNS infections (meningitis, encephalitis) (see these terms), brain malformations (hydrocephalus, arachnoid cysts), trauma and injuries. [orpha.net]

  Such problems include a tumor, brain trauma (such as a blow to the head, brain surgery, or radiation treatment to the head), or inflammation (such as meningitis). PPP is rarer than CPP. [hormone.org]

• Vaginal Bleeding

  (uterine estrogen withdrawal bleeding) bleeding and discharge (from the estrogenic vagina) The first clinical sign of McCune-Albright syndrome is often vaginal bleeding. [endotext.org]

  A 7-year-old female child was presented to the emergency room with acute abdominal pain and vaginal bleeding. [ncbi.nlm.nih.gov]

  Irregular vaginal bleeding was present in three patients. LHRH a significantly decreased basal (P a can be adequately assessed. (N Engl J Med. 1981; 305:1546–50.) [doi.org]

• Hematuria

  Wilms tumor is the most frequent pediatric renal malignancy, and its usual presentation is an abdominal mass or hematuria. [hindawi.com]

Levels of sex-steroids: The measurement of serum testosterone is beneficial to diagnose precocious puberty. It must be noted that the early morning levels of testosterone in boys is higher than the afternoon levels.

The levels of testosterone in different stages of puberty changes:

• Testosterone levels less than 30 ng/dL is considered prepubertal
• Testosterone levels of 30-100 ng/dL is early pubertal
• Testosterone levels of 100-300 ng/dL is mid- to late-pubertal

For girls, the estradiol level measurement is not a reliable method. Determining the levels of adrenal androgens such as dehydroepiandrosterone (DHEA), or dehydroepiandrosterone sulfate (DHEA-S) is a good indicator. In premature pubarche, the levels of these hormones are elevated. Thus, DHEA-S which is the storage form of DHEA is the preferred steroid as its levels are usually high in such patients, thus, helping in correct assessment of the condition.

Random LH level determination is now considered as the best screening test for the diagnosis of central precocious puberty (CPP). The definitive test for the diagnosis of CPP is measurement of LH and FSH levels 30-60 minutes after the stimulation by GnRH.

Radiography: The radiography of hand and wrist can help to ascertain the bone age and estimate the likelihood and speed of CPP [8].

Continuous administration of LHRH and GnRH agonists cause a decrease in the levels of LH and FSH 2 to 4 weeks after the initiation of the treatment through a negative feedback mechanism [9].

Leuprolide acetate: Leuprolide helps to suppress the ovarian and testicular steroidogenesis. It helps to decrease the levels of LH and FSH in the body [10].

Histrelin: This drug is an LHRH agonist and is a potent inhibitor of the gonatotrophin secretion. It helps to desensitize the responsiveness of pituitary gonatotrophin. Long term administration of this drug causes the levels of FSH and LH to decrease. Histrelin implants can provide a continuous release of the drug [11].

The prognosis of the disease depends on the underlying cause. However, without treatment, most girls who have onset of puberty between ages 6 and 8 years, achieves the adult height in the normal range. Boys with precocious puberty, on the other hand, do not achieve average height [5].

Complications

Some of the possible complications of precocious puberty are as follows:

• Short height: Though children with precocious puberty may be tall at first (due to their quick growth and early maturation of their bones), they stop growing earlier than usual which make them shorter than the average as adults. If early diagnosis and treatment of the condition is done, then it can help them grow taller. 
• Social and emotional problems: If the child has earlier puberty than the peers, it can make them extremely self-conscious about their body and may impact their self-esteem with increased chances of depression among them.

Genetics plays a crucial role in the etiology of the precocious puberty. An increase in the body mass index (BMI) is often associated with precocious puberty in girls, though; its impact on boys is still debated.

Thus, body weight and fat mass are two important factors that can influence the onset of puberty among girls. In one study, it was found that the increased BMI at an age 3 and rate of increase of BMI in ages between 3 and 6 years is positively correlated to the early onset of puberty [2].

In a recent report from Denmark, it was found that over the 15-years of the study, the mean age at which the appearance of the breast tissues in girls was visible decreased to 9.86 years from 10.88 years, while the age of the menarche declined slightly from 13.42 to 13.13 years.

In the Chinese study, the mean age of development of breast was 9.2 years while the mean age at menarche was 12.27 years. Thus, from different studies across the world, there was seen a decline in the age of breast development and menarche in girls. The exposure to different chemicals from the environment has been one of the causes of this change [4].

Most of the patients with precocious puberty (especially the girls who are suspected to have central precocious puberty), are healthy. The early CNS imaging studies of these 6-year old and 8-years old girls show no structural abnormalities.

The onset of puberty is a result of the secretion of the hormone gonatotrophin-releasing hormone (GnRH) by the hypothalamus. Some of the mechanisms that suppress the onset of the puberty are:

• HPG axis: Highly sensitive to feedback inhibition by even small quantities of sex steroids.
• Central neural pathways: Suppresses the release of the GnRH pulses.

When there are high-amplitude pulses or release of the GnRH, it causes the pulsatile increase in the levels of the pituitary gonadotropin-luteinizing hormone or LH and follicle-stimulating hormone (FSH).

As the level of LH is increased, it stimulates the production of the sex steroids by the leydig cells of testis in boys and ovarian granulose cells among girls. With these pubertal levels of androgens and estrogens, physical changes are seen in the children, including the enlargement of penis and breast development in girls. Also, the increased FSH levels cause the gonads to enlarge in both the genders, promoting follicular maturation and spermatogenesis in girls and boys respectively.

Some of the abnormalities associated with precocious puberty are as follows:

• Germ cell tumors (such as those secreting human chorionic gonadotropin (HCG))
• Acquired CNS injury which is caused by surgery, trauma, and radiation therapy.
• Congenital abnormalities: Arachnoid cysts, hydrocephalous [5].

Some preventive measures to reduce the chances of precocious puberty among children are as follows:

• Avoiding the children from consumption of the external sources of estrogen and testosterone (steroids) such as dietary supplements, prescription medications for adults etc.
• Encouraging the children to maintain a healthy body weight by exercising regularly.

When the signs of the pubertal development occur at an age earlier than which is considered normal, it is defined as precocious puberty. In girls, the development of these signs of early puberty at age 8 years or younger, and among boys the onset of puberty before 9 years is considered as precocious puberty. Early onset of puberty can cause several problems. Initial growth can make the child grow taller among peers, but this early bone maturation causes linear growth to stop early, eventually leading to short adult stature.

The early appearance of breasts or menses in girls and increased libido in boys can cause emotional distress in some children. From the history and the physical examination, if it is ascertained that the child exhibits precocious puberty, the clinician must differentiate between central precocious puberty (CPP) and precocious pseudopuberty.

While the CPP is gonadotrophin-dependent and causes the maturation of the entire hypothalamic-pituitary-gonadal (HPG) axis, the precocious pseudopuberty is a condition in which there is an increased production of sex-hormone and is gonadotropin-independent. Owing to such differences, the correct diagnosis of the condition becomes critical [1].

When the signs of the pubertal development occur at an age earlier than which is considered normal, it is called precocious puberty. Early symptoms of the precocious puberty must come as a warning signal to the patient and the parents. Thus, knowledge of the condition and the ensuing complication can be very helpful in managing the condition.

1. Stephen MD, Zage PE, Waguespack SG. Gonadotropin-dependent precocious puberty: neoplastic causes and endocrine considerations. Int J Pediatr Endocrinol. 2011; 2011;2011:184502. Published online Jan 27, 2011
2. Ng SM, Kumar Y, Cody D, et al. Cranial MRI scans are indicated in all girls with central precocious puberty. Arch Dis Child. May 2003;88(5):414-8; discussion 414-8.
3. Chalumeau M, Chemaitilly W, Trivin C, et al. Central precocious puberty in girls: an evidence-based diagnosis tree to predict central nervous system abnormalities. Pediatrics. Jan 2002;109(1):61-7.
4. Marshall WA, Tanner JM. Variations in pattern of pubertal changes in girls. Arch Dis Child. Jun 1969;44(235):291-303.
5. Macedo DB, Cukier P, Mendonca BB, et al. Advances in the etiology, diagnosis and treatment of central precocious puberty. Arq Bras Endocrinol Metabol. 2014 Mar;58(2):108-17. 
6. de Vries L, Kauschansky A, Shohat M, Phillip M. Familial central precocious puberty suggests autosomal dominant inheritance. J Clin Endocrinol Metab. Apr 2004;89(4):1794-800.
7. Mamun AA, Hayatbakhsh MR, O'Callaghan M, Williams G, Najman J. Early overweight and pubertal maturation--pathways of association with young adults' overweight: a longitudinal study. Int J Obes (Lond). Jan 2009;33(1):14-20.
8. Armengaud JB, Charkaluk ML, Trivin C, Tardy V, Bréart G, Brauner R. Precocious pubarche: distinguishing late-onset congenital adrenal hyperplasia from premature adrenarche. J Clin Endocrinol Metab. Aug 2009;94(8):2835-40.
9. Carel JC, Eugster EA, Rogol A, et al. Consensus statement on the use of gonadotropin-releasing hormone analogs in children. Pediatrics. Apr 2009;123(4):e752-62.
10. Kim YJ, Lee HS, Lee YJ, et al. Multicenter clinical trial of leuprolide acetate depot (Luphere depot 3.75 mg) for efficacy and safety in girls with central precocious puberty. Ann Pediatr Endocrinol Metab. 2013 Dec;18(4):173-8.
11. Lewis KA, Goldyn AK, West KW, Eugster EA. A single histrelin implant is effective for 2 years for treatment of central precocious puberty. J Pediatr. 2013 Oct;163(4):1214-6.