Minoxidil is making me itch. Is scratching the recipient area 5 months after FUE OK?

It would be best to stop the minoxidil all together until the itch and redness is resolved. The itch signifies some inflammation which could impact your result if not resolved. Has there been a change in the type of minoxidil you are using (Foam vs liquid), do you have dandruff. These are all factors that could play a role in your symptoms. You should definitely with your hair doctor about the new symptoms.

If you are having issues after surgery after using minoxidil you should contact your doctor. You may be experiencing an allergic reaction.

It's common for minoxidil to cause itching in the scalp. You should avoid scratching the recipient area as it could cause folliculitis or more irritation. There are minoxidil formulas which include a soft steroid to minimize irritation and itching. I personally like to use Formula 82.

Your transplanted hair grafts are all grown at this point and you don't have to worry about touching or scratching the recipient area of scalp.  You need to discuss this with your hair transplant doctor to find a better solution for your hair loss to get rid of itching of scalp.

Some patients do experience itching, burning and stinging, or even redness at the application site while using minoxidil, so your reaction is most likely not a cause for concern. Furthermore, although patients can have very different recovery rates, most of the incisions from an FUE procedure should have healed within seven to ten days after the procedure. The grafted follicles are deep beneath the skin’s surface, so after five months it is extremely unlikely that scratching the recipient areas would dislodge them, unless you were scratching hard enough to actually break the skin. All hair follicles go through regular periods of growth and dormancy, so it may take a year or more for you to see your full results.
In some very rare cases, certain patients may have an allergic reaction to minoxidil, so seek medical help right away if you notice a developing rash, itching and/or swelling of the face, tongue, or throat, severe dizziness, or difficulty breathing.

Scratching the recipient area after 5 months does not cause any adverse affect on the result.
Minoxidil usage may cause irritation of the skin, redness, dryness, itchiness and dandruff because of alchol content of minoxidil  and very rarely dizziness or even heart palpitations. It would be better to consider using a lower dose/percentage. 

It likely won't cause any permanent damage at this point unless you scratch really, really vigorously, but you should still see your doctor and talk about something to either ease the itchiness or considering a different treatment plan besides the Minoxodil.

Itching scalps are not normal. You may be developing a sensitivity to minoxidil or have in a problem with seborrhea, etc. -- You should see your doctor for evaluation. 

scratching the recipient area is not a good thing to do as it could cause folliculitis.  See your doctor for medication that will stop the itch.