Sickness. Nausea and obvious sickness are also those two symptoms that will appear earlier than others. No matter how fast your rash is developing, you may feel the sickness in the earliest stages of shingles. The sore stomach will be followed by nausea. This symptom people often mistake as a simple food poisoning. But when your sore stomach is followed by diarrhea and vomiting, you should consider shingles as the main reason.