Medical diagnosis

My prof has assigned a term paper and I need your help! Everyone in my class has been given a unique case study about a person who has just been admitted to a hospital. It turns out that this person needs a medical diagnosis... and it's up to us to figure out what chronic illness he or she might have. I think I have an idea what it might be, but it would be nice to get a second opinion. Can you help me?

Here's the case study:

"Mr. Madison, 38 years of age, went to the emergency department of a major urban medical center three weeks after being discharged from the medical center for treatment of toxoplasmosis. Currently unemployed, he has been living with his partner for the past two years. The admission nursing history was obtained from his partner as it was difficult for Mr. Madison to speak. Before he became too fatigued to work, he was a carpenter/electrician. He occasionally used alcohol, but was otherwise drug-free.

Mr. Madison’s came to the hospital because he had difficulty swallowing and a sore throat. He had more difficulty swallowing cold liquids than hot ones and complained of a burning chest pain while swallowing. His cough was productive of clear sputum, and cultures showed that he had Pneumocystis carinii. He is 5ft 6 in tall and weighs 53.6kg. He also had loose stools for several days. His temperature was 37oC, heart rate 120 beats per minute, respiratory rate 24, and blood pressure 120/78mm Hg. His lungs were clear to auscultation and he had erythematous ulcerations on his tonsillar fossa and under his tongue."