Men's Health :: Dry/Rough Skin On Foreskin Opening

Last night the end of my foreskin went all dry, rough and shriveled up. Rest of the foreskin is smooth as normal.

The skin at the tip of the foreskin mildly red/tender (with white dry skin bits) when my penis is in a flaccid state however during an erection the tenderness and redness is much more pronounced. Pulling the skin back whilst erect is much more painful(although its usually quite painful to do that normally anyway due to my foreskin being very tight during an erection).

This has only happened once before in my life and the doctor said he was convinced it was down to poor hygiene if i hadnt any recent sexual activity other than masturbation. He basically said that I should wash there more often and then prescribed me some cream and it went away a couple days later and did ease all the symptoms while the cream was on tbh (but my paranoia was telling me it would have done on its own anyway). In this case i have been living at someone elses house looking after it while they are on holiday and they have no hot water so havent washed down there in over a week. The obvious answer would be that is the cause but i just wanna make sure.