Hi my son has hair in armpit and genitalia just...

is this normal ?
yes it is considred to be normal if he is above the age of 9 years 
what is the treatment of precocious puberty ?
the treatment is hormonal by gnadotropin relesing hormone such as leuprolide acetate in a form of a monthly injection for 12-16 months till the boy reachs the appropriate up to age growth but in ost of the cases the reatment is not indicated uness the conditon is severe 
what are the diagnostic tests needed in case of precocious puberty ?
in this case the clinical examination and the medical history then the doctor might ask for an x ray for the left hand to check for the physiological age of the boy then an test for thyroid hormone ( t4,t3,tsh ) then an mri scan for the brain to check if there is a brain or hypothalamic tumor 
what are the possible causes of precocious puberty ?

• brain tumor 
• McCune albright syndrome
• cogenetal adrenal hyperplasia 
• hypothyroidesm 
• being an african descent
• history of radiation therapy 

what are the signs of early puberty in males  ?
any of such signs that appears before the age of 9 years old such as 

• pubic hair and armpit hair 
• adult body odor 
• enlarget testicles and penis in boys 
• facial acne 

what is the advice ?
we advice you to visit the family medicine doctor for the right diagnosis and the correct treatment