Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. This certainly doesn t behave like any classic type of pharyngitis or meningitis. You ve not mentioned whether he had a fever or if the sore spot on his back is red, warm to the touch, bulging, etc. However, it certainly sounds as if he s not himself. He may have something as simply as a viral syndrome or he may have an occult infection of the spinal column (though unlikely). He needs a physical examination along with some blood work and urine. Hope I have answered your query. Let me know if I can assist you further.