I had my 2nd Infini treatment done 3 days ago. Can skin laxity in the neck area get worse instead of better? (Photos)

Don't base any judgements on results at 3 days after your treatment.  The treatment involves significant trauma to the tissue, and it take a while to return to baseline.  To see a final result takes 3-6 months.  I have used the Infini for the past 2 years and there have been a couple of patients who I thought did look worse, after treatment.  They too had thin faces, and while not a dramatic difference, it was noticeable on before and after photos.The older the individual, and the greater the degree of laxity, the less likely a significant result will be obtained.  That's just the nature of nonsurgical skin tightening.  At least in my experience, the people who need it the most are the least likely to benefit.  

For decades I have tried many different non invasive treatments to improve neck laxity, horizontal neck creases and muscle bands. I have seen in my NYC practice some improvement with Thermage, Ultherapy, ThermiSmooth, ThermiTight, and now Infini microneedling with radiofrequency energy. What has been impressive is that usually these procedures produce a few days of temporary improvement from swelling but they all take many months after the treatments are done before true tightening is seen and collagen production does take 6 to 12 months to form, but I have seen results sooner with Infini than other treatments.Every patient responds differently to non invasive tightening procedures regardless of the treatment.  I can't imagine anyone developing more sagging or laxity from having Infini but if the results which can take time to see, aren't seen after two treatments I normally encourage the third monthly treatment. However, if it is thought that the results a month after a second treatment is worse than before treatment I might consider my patient waiting six months to see if there is continued improvement and then perform further treatment(s).

Some degree of swelling can be seen with Infini microneedling radiofrequency treatment for a few days especially with higher intensity settings.  This may look like laxity of skin.  I think it is reasonable to give it some time for the swelling to disappear before making further treatment decisions.  Keep in mind that the collagen Infini produces is a slow process over months and the immediate effects are related to heat related to tissue swelling in the dermis.  Best wishes.