A 25 years old patient came to the clinic complaining of cough on and off for 1 year. The cough is nonproductive, and is has worsened in the last 4 months. She feels tired, has occasional low grade fever, mild dyspnea on exertion, and has lost 5 pounds. The patient has no history of asthma or tobacco use. She has experienced intermittent pain in her shoulder and knees. She has also noticed that her vision has worsened in the last two weeks.
She is well nourished and is in no acute distress. There are mobile enlarged anterior cervical and epitrochlear lymph nodes. Pulmonary examination reveals bilateral dry crackles. She has pain with motion. Painful red nodules are seen on her anterior aspect of the legs.
Initial diagnostic plan:
1) chest x-ray: symmetrical bilateral hilar lymph nodes; normal lung parenchyma.
2) complete blood count: normal.
3) purified protein derivative skin test: less than 5mm.
4) acid-fast bacillus and septum culture: negative
5) antinuclear antibodies: negative
based on the history and physical examination, along with the initial diagnostic plan, what are the 3 possible disease states in your differential diagnosis.
What is the most likely diagnosis of this patient? Argue your point.