After receiving an allogeneic hematopoietic stem cell transplant, many people feel "the hard part is over now" and breathe a sigh of relief. But once they are actually discharged and a month, two months pass, suddenly the palms get itchy and red, or a belly that was fine sends a signal with diarrhea several times a day. This is exactly graft-versus-host disease, GVHD for short. It happens when the immune cells received from the donor recognize your body as a "strange place" and attack it, so you can think of it as something like the shadow of the transplant. It does not come to everyone, but its coming does not mean the transplant failed either.
The place where it usually shows first is the skin. The palms, soles, the area around the ears, and the back of the neck flush red and start to sting or itch. At first some people only apply moisturizer thinking "maybe it is just dry," and within a few days the rash spreads to the trunk. In severe cases the skin peels as if badly sunburned. So when you see a change in the skin, taking a photo is surprisingly helpful. Showing it at your next appointment — "it was about this much and then it changed like this" — makes it far easier for the care team to gauge how fast it is progressing.
When it comes to the gut, the symptoms shake daily life a bit more. You feel nauseous and your appetite drops sharply, or watery diarrhea will not stop. When the amount is large, several liters can go out in a day, and what is frightening then is not the diarrhea itself but the water and electrolytes leaving the body. If you feel dizzy and drained, it may be a sign of dehydration, so do not just endure it. One more thing: if the whites of your eyes or your skin take on a yellow tinge, or your urine darkens to a deep brown, it may be a message from the liver. The liver is an organ that does not express itself well through pain, so it is often caught first through blood test values (especially bilirubin).
The key is "how quickly you notice." GVHD often settles with just a medication adjustment if caught early, but if you delay for a few days, it becomes tricky to manage. That is why, around 100 days after transplant, it is good to observe your own body a little more keenly. Taking your temperature at about the same time each day, and noting the number of diarrhea episodes with a rough amount and the location of the skin rash — even if it seems like nothing — becomes a big clue in the exam room. Reducing or stopping immunosuppressants on your own is also forbidden. If you skip the drug thinking the symptoms have improved a bit, GVHD tends to raise its head again in that gap.
And to add one thing, mild GVHD is actually known to have a side that helps prevent the original disease, such as leukemia, from relapsing. So there is no need to be too discouraged just because you got the diagnosis. What matters is not suffering alone. If you see signs like a new rash, diarrhea that will not stop, or skin turning yellow, do not wait for your next appointment — contact the transplant team right away.
This article is put together so you can get a feel in advance for what changes to watch for after transplant. Symptoms and drug adjustments differ from person to person, so be sure to make the actual decisions together with your care team.