Differential Diagnosis for Vasculitis Rash
Given the patient's history of B cell lymphoma and the presentation of vasculitis rash with high WBC and neutrophil count, the following differential diagnoses are considered:
- Single Most Likely Diagnosis
- Leukocytoclastic Vasculitis (LCV): This condition is characterized by inflammation of small blood vessels and is often associated with an elevated white blood cell count. The patient's history of lymphoma and recent development of vasculitis rash make LCV a plausible diagnosis, as it can be triggered by various factors including infections, medications, and malignancies.
- Other Likely Diagnoses
- Henoch-Schönlein Purpura (HSP): Although more common in children, HSP can occur in adults and is characterized by palpable purpura, abdominal pain, and arthritis. The patient's vasculitis rash and elevated WBC and neutrophil count could be consistent with HSP.
- Polyarteritis Nodosa (PAN): This medium-vessel vasculitis can present with skin manifestations, including rash and purpura, along with systemic symptoms such as fever and weight loss. The patient's history of lymphoma and elevated inflammatory markers make PAN a possible consideration.
- Cryoglobulinemic Vasculitis: This condition is associated with the presence of cryoglobulins (proteins that precipitate at cold temperatures) and can cause skin vasculitis, glomerulonephritis, and neuropathy. The patient's history of lymphoma increases the risk of cryoglobulinemia.
- Do Not Miss Diagnoses
- Infection-Associated Vasculitis: Certain infections, such as endocarditis or sepsis, can cause vasculitis. Given the patient's immunocompromised state due to recent chemotherapy, an infectious cause must be ruled out to avoid missing a potentially life-threatening condition.
- Drug-Induced Vasculitis: Various medications, including those used in chemotherapy, can trigger vasculitis. A thorough review of the patient's medication history is essential to consider this possibility.
- Rare Diagnoses
- Wegener's Granulomatosis (Granulomatosis with Polyangiitis, GPA): This rare autoimmune disorder can cause vasculitis, granulomatous inflammation, and necrosis, primarily affecting the respiratory tract and kidneys. Although less likely, GPA should be considered in the differential diagnosis due to its potential severity.
- Ehlers-Danlos Syndrome: This genetic disorder can cause blood vessel fragility and is associated with easy bruising, poor wound healing, and other systemic features. While rare, it could be considered if other diagnoses are ruled out and there are additional suggestive features.
- Paraneoplastic Vasculitis: This rare condition is associated with underlying malignancies, including lymphoma. Although the patient is in remission, paraneoplastic vasculitis could be a consideration if other causes are excluded and there is suspicion of disease recurrence or a paraneoplastic phenomenon.