Differential Diagnosis
- Single most likely diagnosis
- Wegener's Granulomatosis (Granulomatosis with Polyangiitis, GPA): This condition is a form of vasculitis that affects small- and medium-sized vessels. The patient's symptoms, including right-sided back pain, chest pain, nausea, purpura, and elevated inflammatory markers (raised WBC, ESR of 120mm), along with renal impairment (elevated serum creatinine and blood urea), are consistent with GPA. The presence of purpura and burning sensation in these areas further supports a diagnosis of vasculitis.
- Other Likely diagnoses
- Polyarteritis Nodosa (PAN): This is another form of vasculitis that could explain the patient's symptoms, including the purpura, back and chest pain, and renal dysfunction. However, PAN typically does not involve the lungs, which might be less likely given the chest pain, but it's still a consideration.
- Microscopic Polyangiitis (MPA): Similar to GPA, MPA is a form of vasculitis that affects small vessels and can present with renal dysfunction, purpura, and elevated inflammatory markers. It lacks the granulomatous component of GPA but could be considered given the overlap in symptoms.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Infective Endocarditis: Although less likely given the constellation of symptoms, infective endocarditis can present with systemic symptoms including fever, malaise, and embolic phenomena that might mimic some of the patient's symptoms, such as purpura. The elevated WBC count could also be seen in infection.
- Severe Sepsis or Septic Shock: The patient's elevated WBC count, renal dysfunction, and systemic symptoms could also suggest a severe infection. Sepsis is a life-threatening condition that requires immediate recognition and treatment.
- Rare diagnoses
- Ehlers-Danlos Syndrome with vascular complications: This genetic disorder can lead to fragile blood vessels and could potentially explain some of the patient's symptoms, including purpura and possibly the renal dysfunction if there were vascular complications affecting the kidneys.
- Churg-Strauss Syndrome (Eosinophilic Granulomatosis with Polyangiitis, EGPA): Another form of vasculitis that is less common and typically associated with asthma and eosinophilia. The patient's presentation does not strongly suggest EGPA without additional information on eosinophil count or respiratory symptoms, but it remains a rare consideration.