herpes zoste
"I noticed tingling and burning on my left thigh one day, as well as increasingly severe back pain.  Two days later, I had a light rash that I mistook for razor burn along my bikini line on my left thigh.  Two days after that, my OB (I was 31 weeks pregnant) diagnosed me with shingles.  I started Famciclovir the next day (went to PCP who prescribed it...long story).  My PCP mentioned that the back pain was probably a symptom of shingles, that the area of my back in question was linked to the same dermatome as the rash on my leg.  By day 3 on medication, my discomfort had decreased and new sections, while they had appeared, did not blister.  By day 5, my blistered section was mostly scabbed over."