Hello, My Daughters Boyfriend Has Sores On The Tongue And

Hello, my daughters boyfriend has sores on the tongue and swollen gums, chest pains hard time breathing and a fever. went to a walk in clinic yesterday and showed high white blood cells, went to emergency today because of lots of pain. Was put on antibiotics and anti inflammatory pills. They don't have any idea what has caused this or what it is. Any idea. Ex-ray on chest came out fine. Any ideas?