Differential Diagnosis for 88-year-old Man with Bilateral Hand Edema and Itchy Red Skin

Single Most Likely Diagnosis

• Dry skin (xerosis): Given the patient's age and symptoms of itchy red skin, dry skin is a common condition in the elderly, especially during winter months or in dry environments, which can cause itchiness and redness.
• Eczema (atopic dermatitis): Although more common in children, eczema can occur at any age and is characterized by itchy, inflamed skin, which fits the patient's symptoms.

Other Likely Diagnoses

• Contact dermatitis: This is a type of inflammation of the skin that occurs when the skin comes into contact with an irritant or allergen, leading to redness, itching, and swelling, which could explain the bilateral hand edema and itchy red skin.
• Seborrheic dermatitis: This condition causes scaly patches, red skin, and stubborn dandruff, often affecting oily areas of the body like the face, which could account for the bilateral redness on the cheeks.
• Psoriasis: An autoimmune condition that speeds up the life cycle of skin cells, causing cells to build up rapidly on the surface of the skin, leading to scaling, redness, and itching.

Do Not Miss Diagnoses

• Cellulitis: A bacterial skin infection that can cause redness, swelling, and warmth of the skin, which could be mistaken for other conditions but requires prompt antibiotic treatment to prevent serious complications.
• Deep vein thrombosis (DVT): Although less likely given the bilateral nature of the symptoms, DVT can cause swelling and redness in one leg, and it's crucial to rule out this potentially life-threatening condition.
• Lymphoma or other malignancies: Certain types of skin lymphoma can present with skin redness and itching, and while rare, missing a diagnosis of lymphoma could have severe consequences.

Rare Diagnoses

• Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the hands and feet, which could potentially explain some of the patient's symptoms.
• Sarcoidosis: An inflammatory disease that can affect multiple organs in the body, including the skin, causing a variety of skin symptoms including redness and itching.
• Pellagra: A disease caused by a lack of vitamin B3 (niacin), which can lead to dermatitis, diarrhea, dementia, and potentially death if left untreated, characterized by the "three Ds" and could present with skin symptoms similar to those described.