These two sites are awful. They literally only display links that they get paid for. And they don't even do a good job with it. In some cases the affiliate links are a worse offer than others publicly available.
Shingles, a viral infection of the nerve roots caused by the chickenpox virus, can sometimes lead to a painful complication called post-herpetic neuralgia. Sometimes, a physical stress like cold or sunburn can bring on an attack. Even clothing touching the skin or a cool breeze can cause excruciating pain.
Herpes zoster virus causes shingles. No one knows for sure what causes the chickenpox virus to become reactivated to cause shingles. Some investigators suggest that the following conditions may participate in virus reactivation, since they have been associated with a higher incidence of shingles.