This may represent a yeast infection. Usually the underlying skin would be red and inflamed. You can get this if you are taking antibiotics for another problem, but also this can occur if you have sugar in your urine (diabetes).
An allergic reaction to a drug, even though it is not placed in the area, is a possible but unlikely cause, also. This is called a fixed drug reaction.
You can try an antifungal cream and see if this solves the problem, but a urinalysis is a good idea in any case to rule out diabetes..
S.A.Liroff, M.D.
Seems to me that the sinus problem is most likely treated with some form of antibiotic.
This can cause yeast candida to manyfest under the foreskin.
I have had this happen several times while using antibiotics.
Try a cream like Canesten or Monistat. Cover the complete surface of the penis.
Good luck,
Ron
A related discussion,
white layer on penis was started.
Sir this white layer is accumulating in glans,and also in inner forskin layer.layer is wash off during bath.i am nothing putting on my penis.and itching is there during this time.
Your description does not give me enough information to allow even a guess as to what is happening.
Is the whole penis involved? Is there itching? Does the layer wash off? Are you putting anything on your penis? Does it happen only after sex? Any blisters? Pain?
S.A.Liroff, M.D.