Hi!
I'm new to this blog thing, so bare with me LOL! Your question is the reason I decided to sign up. I have been doing nails just shy of 30 years (YIKES! This is just to verify my experiences). I don't want to make assumptions on what type of nails you are doing whether it be acrylic, hard gel, or gel polish. I took a quick look at the pic, couldn't quite tell what was going on. By what you have described it definitely sounds like a reaction. In my experience it can get ugly, yes. But not all is hopeless. I have had many clients (my mother included) that have developed allergic reactions over the years. And yes, they can develop at any time. I have even consulted a dermatologist on this matter years ago. Generally I have found that it starts mildly on the middle and ring fingers (why I don't know) but, a lot of times the client dismisses it and you are unaware till it gets bad. You could be motoring along with this client for years and then it happens. I personally have decided to continue doing their nails BUT, (big BUT) I have had to put my skills to the test. Being Very careful not to contact the skin! What I have found is that the biggest culprit is using a primer. I have moved onto hard gels over 28 years ago and have completely eliminated the use of any primer. For my clients that have this issue I have recommended they follow up their appt with the use of benedryl cream in the case of a flare up. I also recommended that they put off their fillins as long as possible to reduce the exposure. I completely agree with the others, Ciderella and AcidPerm, that if you are Not Comfortable with continuing their service, then by all means Stop! Thing is, you must wait for the flare up to calm down before you attempt to remove them. Too soon and you can make a matter worse. When the skin around the nail is inflamed it can push up into the nail and cause a break in the tissue and then opening up to a staff infection. So the recommendation of a triple anti-biotic cream would be a good idea also. I understand that Neosporin will promote Too much cell growth (coming from a client, the wife of a hand surgeon) so please advise a triple anti-biotic cream. I tell my clients "No to Neo". Whew! sorry for the book! I'm just trying to pack as much personal knowledge as possible into this. I've had to figure things out on my own many times due to the fact that blogs like this were not available. The education of nails is for buying and using product. When it comes to the health and well being of your loyal clients information is less available from a mfg. I'm not slamming the mfg. They are going to give you the best solution to a situation that may carry large liabilities. I have to remember that I have a responsibility to my clients as a professional. I hope this helps.
Take care and much luck in your endeavors!
Jenniffer