Any idea?
John, the " visable red patch " is not shown in the photo … ?
The veins are normal, and these are under a great deal of pressure when you have an erection as the whole penis is engorged with blood - so the veins being clearly more visible are likely to be normal - what you may have is one of the veins is slightly leaking blood during your erection and is creating the visible red patch.
Depending on how long you masturbate for, and the pressure you apply to your penis, particularly the upper-shaft and head area itself, this may be making a slightly weaker blood vessel or vein actually burst or certainly to leak the blood you are seeing in the tiny spots and the red patch.
I wonder what age you are? What may help is if you abstain from masturbation for as long as you can - or if you cannot avoid this then make yourself come as quickly as you can to avoid extended pressure periods in the head of your penis when masturbating.
By abstaining you allow the potential for the vein or blood vessel to naturally heal itself - no good thinking of a few days, or even a week or two - you would need to do this for around 2 to 3 months for healing to take place.
Instead, you could get yourself some baby oil or lotion, or better still, a little LIQUID coconut oil and learn how to massage your penis to gain pleasure - as long as you do not apply too much pressure, and certainly not if you get an erection …