All my adult life, I've had recurring problems with either my feet or my hands developing a severe itch (usually not at the same time), almost always at nighttime (around 11:30 PM), occasionally earlier in the day or where standing. The itch is not confined to my soles but can be the entire foot and both sides of all my fingers. I am a thirty-year old very healthy male. The itch keeps me up at night.
The itch is a deep itch, and there is no rash/eczema/redness, and the itching is not seasonal. It does not respond to corticsteroids (including prescription ones), and it is not contact dermatitis. It does not respond to Hydroxyzine either.
I have ruled out peripheral neuropathy (pain in the extremities due to Diabetes), and my blood sugar and liver blood tests all come out fine.
The itch is not athletes foot (I know because I have had athletes foot), and wouldn't apply because it's on my hands occasionally.
The itch is not due to dry skin because I 1) use moisturizers, 2) live in very humid San Francisco, and 3) it is a deep itch with no visible symptoms.
I do have a history of depression, but I have noticed no correlation between the itch and depression and stress. It still occurs at some of the least stressful times of my life. If there is a correlation with stress, it's because the itch itself is stressful.
The only relief I have discovered are cold compresses. I have a freezer full of them. Heat does not help. People have spent time with me can testify about how strong this itch is. It occurs 2-3 times a week and takes about an hour before it calms down. The odd thing is it occurs only at night.
My current best theory is it may be due to a hormonal problem. In light of this itch manifesting itself only at night, a circadian hormonal spike or imbalance makes sense. Pregnant women report itchy hands.
Another theory is a metabolic intolerance. If I eat something I can't metabolize during the day, the itchiness would therefore only show itself at night as whatever I can't digest builds up. I can't find any correlation with it and my diet, however. Recently, I was assaulted and had to spend two days hospitalized. The second night, the itch showed up (the nurse thought I was crazy asking for ice rather than a sudafed: I told her the sudafed wouldn't work), but I hadn't been allowed to eat anything, so It couldn't be metabolic.
That leaves dietary deficiency - my body needing something, but I regularly take a multivitamin. Also possible is dietary over-eating (I pledge guilty to too much processed food and sodium), but, again, no correlation as far as I can see.
I have read about 10+ postings across the magikall interwebs describing the same phenomena in others, all with stupid follow up suggestions about athletes foot, et. al. If there is a reasonable theory of what is going on with this itch out there, I would much like to hear about it!