From your description, it does not seem like you are really suffering from a fungal infection. This might be some other sort of infection, and may have affected the surrounding or underlying tissues, rather than the nail itself. Fungal infections of the nail are usually painless, and affect the nail itself and the nail bed. Such infections (known as onychomycosis) do not cause blisters, nor do they cause pain. The absence of pain is one reason why people tend to ignore these infections till the nail starts looking really unpleasant. With nail fungus, the nail itself typically develops a cloudy, yellowish appearance. The affected nail also seems to be crumbling, and becomes rough in texture. The nail may actually start to fall apart, or it may become loose and separate from the underlying tissue. Except for the nail beginning to fall off, you have not mentioned any such symptoms, so it is unlikely that this is a case of onychomycosis. If untreated for a really long time, a nail fungus infection can eventually cause pain and inflammation, but the absence of any other typical symptoms seems to indicate some other cause. In any case, if a fungal infection of the nail is causing pain, it means the infection has progressed quite far and needs prompt medical attention. It is advisable that you consult a doctor right away, as you have already waited for a month.
At this stage, topical medication may not be enough, and you may need oral medication too. Your doctor may also decide to remove the affected nail, but it will of course grow back, so there is no need for you to worry. Remember that the longer you wait, the more likely it is that the nail will need to be removed. Along with whatever medication your doctor prescribes, you will need to be very careful about hygiene. Keep the affected nail, and in fact both your hands, clean and dry at all times. Moisture and poor hygiene will worsen any infection and should be avoided. In addition, you can try applying a warm compress to the affected finger several times a day. This usually helps a boil or blister to drain more rapidly. However, in your case this is unlikely to solve the problem by itself, so be sure to make a doctor's appointment, and ask your doctor's opinion before you actually do anything.
answered by M W