Differential Diagnosis for Annular Rash with Distinct Borders and Scaly Center
- Single most likely diagnosis
- Tinea corporis (ringworm): This is the most common cause of an annular rash with distinct borders and a scaly center. It's a fungal infection that can affect any part of the body, characterized by a circular, itchy, and scaly lesion.
- Other Likely diagnoses
- Nummular dermatitis: This condition presents with coin-shaped lesions that can have a scaly center and distinct borders. It's often seen in individuals with a history of atopic dermatitis or dry skin.
- Granuloma annulare: A benign skin condition characterized by a ring-shaped lesion with a scaly center, often found on the hands and feet.
- Lichen planus: An inflammatory condition that can cause annular lesions with a scaly center, typically seen on the skin and mucous membranes.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Lyme disease (erythema migrans): Although less common, Lyme disease can present with an annular rash (erythema migrans) that has distinct borders and a scaly center. Early diagnosis and treatment are crucial to prevent long-term complications.
- Cutaneous T-cell lymphoma (mycosis fungoides): A rare type of skin cancer that can cause annular lesions with a scaly center. It's essential to consider this diagnosis to ensure timely treatment and prevent disease progression.
- Rare diagnoses
- Sarcoidosis: A systemic disease that can cause skin lesions, including annular rashes with scaly centers. It's a rare condition, but considering it in the differential diagnosis can help identify patients who require further evaluation.
- Erythema annulare centrifugum: A rare skin condition characterized by annular lesions with a scaly center, often associated with underlying infections, inflammatory diseases, or malignancies.