Because Roberta (and I) have had our CAH daughters die. We have also run across several other people who have had a CAH person die from just vomiting once the night before. Literature states that a CAH child who is tired or lethargic may be experiencing low blood glucose. AND low blood glucose (30 or below) can cause brain damage, seizures, coma, and death. Any vomiting can be potentially fatal and it does not matter what the age of the person is, I've heard about several adults who nearly died from just 2-3 times vomiting. A child can be dehydrated from their salt balance being off and not yet have any other dehydration systems. CAH children can die within 8-24 hours of an illness onset, any vomiting can be fatal so, so quickly (like within 6 hours). Regarding a CAH child "vomiting severly for 3 days" -- my research says that most probably would not happen because a CAH child would not live 3 days if vomiting. A tired-looking CAH child who is vomiting needs to go to the hospital for IV hydrocortisone, IV saline & IV glucose. Vomiting may be the first sign of an adrenal crisis (that the salt-potassium balance is off), vomiting in a CAH child may not be because of illness. Low salt will cause vomiting. Regarding high fevers that won't come down, a fever that won't come down is an indication that the child is entering dehydration (even though no other symptoms yet). With illnesses (fever and/or vomiting), you don't know how well the cortef is being absorbed into their system, the mechanics of the way illnesses work may be preventing the cortef to be properly absorbed. IV solu-cortef is best, IM solu-cortef may not work (the body systems may not carry the IM solu-cortef around). IM solu-cortef will most probably hardly work if the child is dehydrated even a little bit. Blood glucose is needed to keep the sodium-potassium cellular pump working.