Differential Diagnosis for Lower Back Rash in an 83-year-old Female
- The following differential diagnosis is organized into categories to guide further investigation and management.
Single most likely diagnosis
- Herpes Zoster (Shingles): This is the most likely diagnosis due to the patient's age and the common presentation of shingles as a painful rash on one side of the body, often on the trunk, including the lower back.
Other Likely diagnoses
- Contact Dermatitis: This is a common condition that can occur at any age, caused by exposure to allergens or irritants, which could lead to a rash on the lower back.
- Eczema (Atopic Dermatitis): Although more common in children, eczema can persist into adulthood and cause a rash on the lower back.
- Psoriasis: This chronic skin condition can cause a rash on various parts of the body, including the lower back, and is more common in older adults.
- Fungal Infections (e.g., Tinea Corporis): Fungal infections can cause a rash on the lower back, especially in warm, moist areas.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Meningitis: Although less likely, a rash on the lower back could be a sign of meningitis, especially if accompanied by fever, headache, and stiff neck. Early recognition and treatment are crucial.
- Sepsis: A rash could be a sign of an underlying infection leading to sepsis, a life-threatening condition that requires immediate medical attention.
- Vasculitis: Certain types of vasculitis, such as Henoch-Schönlein purpura, can present with a rash and have serious complications if not treated promptly.
Rare diagnoses
- Pityriasis Rotunda: A rare skin condition characterized by circular, scaling patches, which could appear on the lower back.
- Lichen Planus: An inflammatory condition that can affect the skin, causing a rash, and is more common in older adults.
- Cutaneous T-cell Lymph Desserts (CTCL): A rare type of skin cancer that can cause a rash, which may appear on the lower back.