Dr. Roach: Bruise discoloration on foot isn’t from a blood clot
Dear Dr. Roach: I’m a 68-year-old woman in good medical/physical condition. I run three times a week and work out with weights regularly. The only medicine I take is bioidentical hormones. Recently, the side of my foot near my baby toe felt sore as if, when I walked, I was stepping on a small pebble. It’s not really painful, but annoying. This started about midday and continued throughout the day. The following morning, I woke to find the same part of my foot darkly discolored as if I’d had a bad injury. The bruised covered about a quarter of my foot. By the next morning, the discoloration had completely resolved. There was no other pain. What caused this -- perhaps a blood clot? Could this be a warning sign of something more serious? The only other time this happened was to my big toe a few years ago, and then it was exactly the same, some soreness, the bruised appearance and then complete resolution the following day.
![Dr. Keith Roach](/gcdn/presto/2020/09/08/PDTN/48a1731f-5678-4d20-a2cd-0aaf0471dae6-Dr_Keith_Roach_with_bkg.jpg?width=300&height=352&fit=crop&format=pjpg&auto=webp)
— M.J.M.
Dear M.J.M.: A bruise is the usual term for what medical professionals call a hematoma, a collection of blood located outside the blood vessel. I believe that’s exactly what you had. Runners and other active people get trauma to their feet, and a small blood vessel can break, letting blood collect inside the tissues. Gravity usually pulls the blood down, often to the skin, where the discoloration can be noticed. Your bruise resolved quickly, within a day, suggesting that the blood internally was not a lot of volume, but was spread out over a large area.
I do not suspect a blood clot in a vein. That usually shows up with swelling, since the blood isn’t being drained properly and fluid literally backs up behind the blockage. Estradiol, the bioidentical major human estrogen, does predispose a person to clotting, but even so, what happened to you still doesn’t sound like a clot. Discoloration is unusual, although sometimes a clot can be felt as a hardness in the blood vessel.
Dear Dr. Roach: I live in a very sunny climate (250 days per year) and wear sunscreen year-round. Do I still receive enough sunshine through my skin layers for adequate vitamin D production? Or does sunscreen interfere with this process?
— T.D.
Dear T.D.: The skin needs exposure to light in order to produce vitamin D. So, in theory, your concern is valid. Extremely careful application of sunscreen greatly reduces the amount of vitamin D our body can produce from light-induced conversion of active vitamin D in the skin. In real life, however, few people apply sunscreen so well that they get to the point of a low vitamin D level.
In lighter-skinned individuals, just 10 minutes of sunlight on the face and hands is enough to prevent vitamin D deficiency. If you are going outside, you are probably getting enough sunlight (at least in the summer, when the stronger sun is more efficient at helping the body produce vitamin D) even with sunscreen.
People who wear sun-protective clothing all the time, or those who almost never go outside, are at higher risk for low vitamin D levels and should be considered for vitamin D testing. I’ve seen a great deal of skin cancer, and I believe it’s the right decision to protect yourself from skin cancer with appropriate sun-protective clothing and sunscreen, and take vitamin D if you need to.
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