Differential Diagnosis for Sudden Onset Patchy, Non-Contiguous Pruritic Rash
Single Most Likely Diagnosis
- Chemotherapy-induced rash: This is a common side effect of various chemotherapy agents, including those used in the ICE (Ifosfamide, Carboplatin, Etoposide) regimen. The timing of the rash, occurring after the completion of a chemotherapy cycle, supports this diagnosis.
Other Likely Diagnoses
- G-CSF-induced rash: Granulocyte-colony stimulating factor (G-CSF) can cause a rash, although it is less common. The administration of G-CSF today could be a contributing factor.
- Drug reaction: Other medications, including antibiotics or antiemetics, could be causing the rash.
- Pruritus associated with Hodgkin lymphoma: Some patients with Hodgkin lymphoma experience pruritus, which can be severe and may be accompanied by a rash.
Do Not Miss Diagnoses
- Neutropenic sepsis with rash: Although less likely, a rash can be a sign of a more serious infection, such as neutropenic sepsis, which requires prompt attention.
- Graft-versus-host disease (GVHD): If the patient has received a stem cell transplant, GVHD could be a consideration, although it is less likely in this scenario.
- Sepsis or infection: Any new rash in an immunocompromised patient should prompt consideration of an infectious etiology.
Rare Diagnoses
- Sweet syndrome: A rare condition characterized by a sudden onset of fever, leukocytosis, and tender, erythematous skin lesions.
- Erythema multiforme: A skin condition characterized by target lesions, which can be caused by infections, medications, or other factors.
- Paraneoplastic pemphigus: A rare autoimmune disorder associated with certain types of cancer, including lymphoma.