Differential Diagnosis for a Very Large Well Circumscribed Uniform Annular Lesion on Top of Heel in a Diabetic Lady
- Single Most Likely Diagnosis
- Diabetic foot ulcer with a surrounding callus or hyperkeratotic border: This is a common complication in diabetic patients due to neuropathy and poor wound healing. The location on the heel, a pressure point, and the description of the lesion are consistent with this diagnosis.
- Other Likely Diagnoses
- Eczematous dermatitis (e.g., contact dermatitis, atopic dermatitis): Could present as an annular lesion, especially if there's an allergic reaction to footwear materials or if the patient has a history of atopic dermatitis.
- Psoriasis: Can present with well-defined, uniform plaques, and the heel is a common location. However, the annular shape might be less typical without other characteristic features like scaling.
- Tinea pedis (athlete's foot): Fungal infections can cause annular lesions, especially in the context of diabetes, where impaired immunity and neuropathy can predispose to infections.
- Do Not Miss Diagnoses
- Squamous cell carcinoma or other skin malignancies: Although less common, any persistent or changing skin lesion, especially in a diabetic patient who may have compromised sensation and healing, warrants consideration of malignancy to avoid delayed diagnosis.
- Deep tissue infection or abscess: Given the patient's diabetes, there's a risk of underlying infections that could be life-threatening if not promptly addressed. The presence of a large, well-circumscribed lesion could potentially mask an underlying infectious process.
- Rare Diagnoses
- Granuloma annulare: A benign skin condition that can cause annular lesions, though it's less common on the heel and might not typically present as a single large lesion.
- Annular lichen planus: Could present with annular lesions, but this condition is less common and might be accompanied by other symptoms like itching or lesions in other areas.
- Subcutaneous fungal infections (e.g., chromoblastomycosis): These are rare and typically occur in immunocompromised individuals or after traumatic inoculation. They could present with large, well-circumscribed lesions but are less likely in this context.