The Italian love doll that is my wife is as white as they come: Blonde, fair skinned, etc… One thing I’ve noticed that I’ve yet to have explained to me is this: approximately 1 week before her period, the inside of her thighs appear as though they are very tan. They turn dark brown. WTF? 
Whatever it is, it’s happening under the skin. This is not some staining happening from discharge or anything like that. I’ve implored my woman to ask this question of her doctor to no success. Anyone here have a clue?
Bizarre. No, I confess, I’ve never heard any woman discuss such a body-change, nor experienced it myself. Do no other parts of her body change color? What happens when her period comes - does the color simply disappear, or does it fade slowly over the course of a week, or…?
I can’t imagine it’s actually a tan, because that would be the skin itself, not under the skin.
Changes in hormones can cause changes in skin color. When I was pregnant my lower abdominal area developed tan patches although I’m glow-in-the-dark white normally. My doctor said it was from hormones and told me it was fairly normal. He didn’t give me a more in-depth and I’ve never experienced it since.
Extra info:
This has been happening to her over the last 24 years.
No other skin tone changes like this have happened, included during the pregnancy of our offspring (now 23, 21, and 18)
IANAD, but if it’s been happening for 24 years, and she’s healthy otherwise, I wouldn’t sweat it. You may want to ask her to ask her doctor at her next OB/GYN exam, if for no other reason than to set your mind at ease.
Oh, I’m not worried about it. I’m just curious as to why it happens. How the heck hormones can make a person appear tan is what confuses me. And in the same spot every month!
I’ve tried to get her to ask her doctor, but she never does.
Just out of curiosity, what PART of Italy? I’m guessing far north. Most southern Italians seem to embody the swarthy Italian stereotype.
My skin does this. The insides of my thighs and the area under my breasts. Really anywhere there is semi-constant skin on skin contact.
I’ve not noticed a monthly difference, but I’ll keep and eye out and let you know.
I have brown inner thighs. I’ll monitor them to see if they darken during my menstrual cycle.
I file this under “normal” by the way.
Reggio di Calabria, though her father was originally from porticello, sicily. Her family was running some kind of resort when they came over here by other relatives and opened up some night clubs and restaurants.
Stereotypes are just that, and nothing more. 
Her mother was half German, I might add.