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Does anyone know how long you have to be on Prednisone before it starts lowering your immune system? Is once you start it, after 3 weeks, 6 weeks, etc? Also, when do some of the side effects such as acne and moon face set in? How long does it typically take?
This is a tricky question, but a good one! If I remember correctly from when my son was on prednisone, the immune suppression builds up somewhat gradually, but we were told to be cautious about exposure pretty much right away since he was going to be on them for 12 weeks. I think if you are on a very short course, like one week, there may not be much of an immune-suppressing effect.

As far as side effects, that also probably varies a lot. My son definitely got the increased appetite right away, which normally would be a good thing, but he was on such a restricted diet at the time that it was just frustrating for him. He also got acne and moon face within a couple weeks, and that faded gradually, but didn't go away completely until a few weeks to a month after stopping. His most annoying side effects from his perspective were sleeplessness, which started within days and lasted the whole course, and pretty strong mood swings, which he got better at managing over the course of taking them, but were pretty unpleasant. Those went away gradually, and even improved as he tapered to a lower dose before stopping.
I believe the immunosuppression occurs as soon as you are on high dose steroids ( doses given to treat IBD). (Immune system changes can be seen after one dose.) My understanding is that people are at higher risk for infection during the time they are on high dose steroids.


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For us, it seems to depend on the dose. If my daughters are on a low dose, like 10 mg, side effects are minimal. But if they're put on 25 mg- 40 mg, well, then side effects show up quite quickly.
If they're on a high dose, like 40 mg, then some side effects start immediately - insomnia, puffy face, increased appetite, retain water etc. Sometimes it affects their mood and they get irritable or moody (this was a much bigger issue when they were teens!).

One of my daughters has few side effects if she's put on a dose like 20-25 mg. She'll get a slightly puffy face and will be hungry and will eat more, but doesn't really gain weight. She tends to have more energy and so she takes Prednisone in the morning so it doesn't interfere with sleep.

My younger daughter used to be similar, but she was on steroids a LOT for 6 years and developed Cushing's syndrome. So now whenever she's put on steroids, she had major side effects, even on 25 mg of Prednisone. She gets the "moon face" immediately (in a couple days!), gains weight really easily, retains water and her whole body looks puffy. She has trouble sleeping at night, is hungry all the time and always gains weight - even if she's really careful about what she eats. She has stomach pain and heartburn with steroids, even if we use a PPI like Prilosec.
BUT she really was on steroids a lot (for years) and so developed both adrenal insufficiency and Cushing's Syndrome.

We've never dealt with acne. But with the moon face, it depends how long your child has been on steroids. Typically it should go away in a few weeks. And water weight goes away quickly too, but if he has been eating more and has gained weight, it may take him some time to lose that weight (if he does at all).
Also, we just increased my son’s Humira frequency from biweekly to every 10 days. Tomorrow will be his first dose of the 10 day frequency. Does anyone know how long it typically takes to know if the increased dose is going to help with active IBD symptoms? How long do we give it before we go to weekly? Just curious so I know what to expect.

my little penguin

Staff member
When humira at 10 days works
Depends on the kid and the amount of inflammation present
When to switch depends on the doc
Each time Ds switched frequency to less days he wax able to stay at that level for at least a year or so


Staff member
We were told to give it 3 months before switching to weekly Humira. Every 10 days was not frequent enough for my daughter, so at 3 months, her doc bumped it up to every 7 days and added Methotrexate. That combination worked like magic for her!


Well-known member
Prednisone: it really depends on the kid. You will get a very varied response here. MY daughter has been on high IV doses and then 40 mg for weeks and she experiences no side effects except for maybe a little moon face and increased appetite but it is seriously not noticeable to anyone but us. How long it takes to work? Also depends on the kid and the disease. My daughter has been inpatient on high IV doses and it has done nothing. Other times she has just had a normal flare and been put on 40mg daily and within days the flare was under control.

Humira: When my daughter went from bu weekly to weekly we were told to give it 6-8 weeks before we assessed whether or not it was working.But it really depends on the level of inflammation and the doc. For minor inflammation some docs are willing to wait longer as the risks of waiting aren't so high but others won't wait too long because ideally minor inflammation should be easier to control. Same is true for high inflammation. The risks go underrated inflammation are higher so some docs will make the move faster while others might say, it takes longer to control the inflammation.
We were told to give it 3 months before switching to weekly Humira. Every 10 days was not frequent enough for my daughter, so at 3 months, her doc bumped it up to every 7 days and added Methotrexate. That combination worked like magic for her!
@Maya142, Did/Does your daughter have bleeding as one of her main symptoms? That’s wonderful the combination you mentioned worked like magic and I’m praying we can find that for my son.