R.L.
Hi A.,
Have there been any other symptoms, like fever, fatigue, irritability that would suggest a viral infection? For most viruses those symptoms could precede the blisters by 3 to 10 days.
If the blisters are actually somewhat translucent, clearly contain fluid, and are now drying up, they're most likely viral in origin, not bacterial. Reasonable culprits would include some kind of herpes virus such as Varicella zoster (chicken pox) or Herpes simplex type 1 (primarily oral infection)or 2 (genital herpes). Sores from Herpes simplex can show up on skin, not just on the mucosa (like inside the mouth). It can be spread to the fingers if there is an active infection in the mouth, and also then to the eyes if rubbed. This type of herpes is known as Herpes whitlow. If your daughter's been spitting and has active herpes virus in her mouth, she could possibly have infected the area around her chin with virus containing saliva. BTW, not all Herpes is sexually transmitted, although most infections are spread through direct contact with saliva or mucous of an infected person. In fact, most of us are infected with the type that causes cold sores (type 1) by the time we're adults, with at least 50% of infections occuring in childhood. Herpes transmitted vertically (from mother to child) usually occurs if the mother is actively shedding virus from the vagina at birth. It IS possible to have primary genital herpes and not not noticable symptoms, BTW.
Also, I have never heard of anyone contracting herpes via vaccination. The attenuated chicken pox vaccine can cause mild fever and body aches, but not a rash. If the vaccine DOES cause a rash, it's defective and the batch should be reported.
As far as getting viral titers checked at a nebulous time in the future, this will usually only tell you if you've had the virus sometime in the past (the test will show that you have viral IgG, indicating that you have mounted an immune response to the virus sometime in the past and are probably immune to new infection). This is not to say that you can't be tested for an active viral infection -- you can, and the company I work for makes a lot of these tests. But, if you don't have active symtoms it is highly unlikely that you will test positive for viral IgM, which is the indicator of active disease. (Some people do make IgM for years after infection, though, so it is possible to be IgM positive and not have an ongoing infection). OK -- this is getting messy and probably not the best place for a university lecture on virology and viral diagnosis.
Going on: if the blisters are actually more like raised red bumps that look more solid and inflamed, and have a lighter pinkish fringe around them, they could be bacterial. Yeast usually shows up as a flattish rash, sometimes with very tiny bumps, so it doesn't sound like yeast from the infection.
My advice would be that, since they're healing it's probably not necessary to do anything but keep them clean and keep an eye on them. If they spread around her mouth or occur elsewhere on her body, definitly go to the doctor. If she develops a fever, body aches, fatigue, etc., go to the doctor ASAP (could be nothing, but could be a secondary infection or early sepsis -- rare, but it does happen). If the sores begin to weep, turn black or smell odd, go to the doctor ASAP. Those are clear signs of a bacterial infection that is not being outgunned by your daughter's immune system. In other words, if you have any concern at all, go to the doctor!
I'm sure all will be just fine,
R.
