Pain from outer edge of big toe nail down to base of toe/top of foot
nail infection? superficial nerve entrapment?
After a hike 5 days ago, I noticed some pain in my left big toe which I attributed to the shoes I was wearing. Since then, I have noticed that I have a very small amount of swelling along the outer edge of that nail, and that it seems to be connected to something that is inflamed and protruding slightly (tendon? ligament?) on the top of my foot, right above the ball of my foot. There is some very vague pain when doing normal activity in the toe, but when pressing on the top of my foot above the ball, towards the inner edge of the foot, I feel an almost electric, painful tingling sensation that connects up to the outer edge of my nail, where the swelling is.
You may actually have two issues going on here, both of which could have occurred from hiking. Let me give you the disclaimer and tell you I am only looking at a picture and your narrative. I enlarged your picture and it does appear to be slightly erythematous (red) and swollen on the inside portion of your nail. In most cases this is the beginning of a paronychia or infection of the nail fold. Something as innocent as a lot of walking may create this problem.
Since I only see the ones that progress to a larger infection, I cannot tell you if your problem will resolve by itself or not. Assuming you are not a diabetic, nor are you a smoker, you can wait a few days and see what happens.
In many instances these irritations will resolve themselves. You might want to wash the toe well with soap and water and rub a little neosporin or bacitracin, or equivalent into the area to try and help matters along.
If the area does not begin to resolve itself in a few days, or certainly if it becomes more red, more swollen and more painful, then you would be well advised to see a foot specialist in your area. Needless to say, if you start to see drainage coming from the nail, that too would be an indication that there may be an infection brewing.
In an otherwise healthy individual a small infection is not that big of a deal, but when an infection of the nail fold persists there is always the chance that it could spread into the bone, due to the obvious close proximity of skin to bone in the toe. That becomes a game changer as bone infections are a much more serious problem than simple skin infections. In my career I perhaps have had two instances of such a situation and if my memory serves me correctly, in both cases they were the result of large draining nail infections that the patients had had for quite a while and finally got around to doing something about it.
Of course there is also the possibility that the redness and swelling is nothing more than inflammation from the nail butting against your hiking boots. I have no way of knowing by just looking at a picture.
As far as the tingling that is coming from the top of your foot into the toe, that is probably a different issue. Tingling that seems to travel is usually indicative of nerve involvement.
In this case we are talking about the medial dorsal cutaneous nerve. This is a nerve that travels just below the skin and gives us the sensation that we feel when we touch the top of our big toe as well as the second and third toe.
If you look at the yellow lines that I have added to your picture you will see the course of the nerve.
One question that your narrative and picture fail to answer is whether or not the lump that you have circled is hard or soft. By looking at the picture the lump appears similar to the other lumps on the top of your foot which are superficial veins. If the lump is soft than it is probably a vein. If, however, it is hard, then it may represent a bone spur as they are fairly common in that area of the foot. Lastly, there is also the possibility that it is a thickening of a tendon, but I have no way of knowing just by looking at the picture.
Since I have no real idea as to what structure it is, but assuming it was not there prior to your hike, you may have created some irritation; simple over bending of the toe from so much walking may have created some type of inflammation and the medial dorsal proper digital nerve, (the yellow arrow going into the big toe) may have become irritated.
Since we can assume this is all a result of excessive activity, then it may just quiet itself down with some rest. If you can tolerate anti-inflammatory medication, then that may be helpful as well. If, however, the tingling persists longer than ten days and does not seem to be resolving, it might be wise to have it examined by a local foot specialist because nerve irritations are best treated when they are fresh.