Differential Diagnosis

The patient's symptoms of worsening fatigue, constipation, nonproductive cough, painful bumps on the legs, and nonpruritic facial eruptions, along with enlarged cervical and axillary lymphadenopathy, suggest a systemic condition. The differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis
  • Sarcoidosis: This condition is characterized by the formation of granulomas in various organs, including the lungs, skin, and lymph nodes. The patient's symptoms of nonproductive cough, fatigue, and skin eruptions, along with lymphadenopathy, are consistent with sarcoidosis. The presence of violaceous, indurated nodules on the shins, known as erythema nodosum, is also a common manifestation of sarcoidosis.
• Other Likely Diagnoses
  • Lupus: Systemic lupus erythematosus (SLE) can present with a wide range of symptoms, including fatigue, skin eruptions, and lymphadenopathy. The patient's nonpruritic facial eruptions could be a manifestation of lupus.
  • Lymphoma: Although less likely, lymphoma could explain the patient's lymphadenopathy, fatigue, and skin symptoms.
• Do Not Miss Diagnoses
  • Tuberculosis: Although the patient's symptoms are not typical for tuberculosis, it is essential to consider this diagnosis due to its potential severity and the need for prompt treatment. A nonproductive cough and lymphadenopathy could be indicative of tuberculosis.
  • Hodgkin Lymphoma: This diagnosis is crucial to consider due to its potential severity and the need for prompt treatment. The patient's lymphadenopathy and systemic symptoms could be indicative of Hodgkin lymphoma.
• Rare Diagnoses
  • Erythema Induratum: A rare condition characterized by recurrent, painful nodules on the legs, which could explain the patient's skin symptoms.
  • Granulomatosis with Polyangiitis: A rare autoimmune disorder that could explain the patient's symptoms of nonproductive cough, fatigue, and skin eruptions, along with lymphadenopathy.