my husband (66 yrs old) has been experiencing excruciating pain in his left buttock and back/outside of his left leg/foot for 7 days. Friends who has had sciatica thought it must be his sciatica pain but no back pain. His doctor thought it is piriformis syndrome . He stands on his left leg to play his musical instrument for a long period of time and his buttock and leg muscle has been bothering him after his gig lately. He describes his pain as shooting, electrical pain . No numbness, tingling or weakness. No back pain. Yesterday he noticed a few small clusters of rash on left side of his mid back and on side of his left foot. He thought they were bug bites. Today he has developed more small clusters of blistered rash on top of his left foot, and ankle to lower leg. Rash is itchy and painful. Could it be shingles? Could it affect sciatic nerve?