Differential Diagnosis for Pruritic Rash in 72 YOM
Single Most Likely Diagnosis
- Diabetic Dermopathy: Given the patient's poorly controlled type 2 diabetes (A1C of 10.1%), diabetic dermopathy is a strong consideration. It is a common skin condition associated with diabetes, characterized by pruritic skin lesions.
Other Likely Diagnoses
- Urticaria: Could be a cause of pruritic rash, though the absence of other symptoms like angioedema or a clear allergen exposure makes it less likely.
- Eczematous Dermatitis: Atopic or contact dermatitis could present with pruritic rash, and the patient's elevated ferritin could be a marker of inflammation.
- Pruritus due to Iron Overload: Elevated ferritin levels (862 ug/L) suggest iron overload, which can cause pruritus, though this is less common.
Do Not Miss Diagnoses
- Hematologic Malignancy: Although the CBC is normal, significantly elevated ferritin levels can be associated with hematologic malignancies like lymphoma or leukemia. It's crucial to investigate further to rule out these potentially deadly conditions.
- Polycythemia Vera: A myeloproliferative disorder that can cause pruritus, especially after warm baths or showers, and is associated with elevated ferritin levels.
Rare Diagnoses
- Porphyria Cutanea Tarda: A disorder of porphyrin metabolism that can cause blistering skin lesions and pruritus, associated with elevated ferritin levels due to iron overload.
- Notalgia Paresthetica: A rare condition characterized by pruritus in the upper back, which could be considered if the rash is localized to this area.