Hi Eveie,

I hope this explanation of Simple Virilizing CAH will help you:

Basically, there are two classifications of CAH 1) Classical and 2) Nonclassical.  Within the classical form, there are two further differentiations 1) Salt-Wasting and 2) Simple Virilizing.  Thus, SV is the milder form of Classical CAH. 

All CAH is characterized by an enzymatic defect, most commonly that of the 21-hydroxylase enzyme, which is needed to produce cortisol and aldosterone.  The relative severities of CAH have to do with the degree that one can or can't produce 21 OH.  From most severe to least severe you would, therefore, have 1) salt-wasting 2) simple virilizing and 3) non classical.  A complete, or near complete, enzymatic block would result in salt-wasting, which results in a potentially life-threatening adrenal crisis within the first few weeks of life. 

With salt-wasting CAH, both cortisol and aldosterone production are impaired.  The deficiency in aldosterone also causes low serum sodium and high serum potassium. With SV, cortisol production is impaired, but aldosterone is normal; however, plasma renin may be elevated.  Florinef is given to normalize plasma renin---that is why your daughter needs it.  Joan W. gives a very detailed explanation of renin under the thread "Reily--Renin Level," currently on page 2, of this MB---you may want to check it out. 

All forms of CAH, caused by 21 OH deficiency, result in excessive androgen secretion and some amount of virilization.  Again, the degreee of virilization is usually most severe with the salt-wasting form, and least severe with the non-classic form.  Girls who are salt-wasters or simple virilizers can present with genital ambiguity, while boys do not.  The fact that your daughter was not born with any sort of genital ambiguity probably means she is on the milder end of the SV scale.

Without treatment, however, post-natal virilization can still occur.  For girls, that means progressive clitoral enlargement; and, for boys, progressive penile enlargement.  For both sexes, non-treatment also results in advanced bone age and early skeletal maturation.  That is why your daughter needs the cortef. 

I don't believe your pediatrician is correct in stating that your daughter cannot have an adrenal crisis.  While it's true that she would probably not have one under normal circumstances, she could still go into crisis if she becomes severely ill, gets into a car accident, has major surgery, etc., so it's probably better to be safe, rather than sorry.

Again, hope this helps....have a Merry Christmas!