Differential Diagnosis for Painless Nodules on Legs
Single Most Likely Diagnosis
- Erythema nodosum: This condition is characterized by the sudden onset of painful or painless nodules, typically on the lower extremities, and can recur annually. The nodules usually resolve on their own within a few weeks to months.
Other Likely Diagnoses
- Nodular vasculitis: This condition presents with recurrent, painless nodules on the legs, which can resolve and recur over time. It is often associated with an underlying condition such as tuberculosis or an autoimmune disorder.
- Cutaneous sarcoidosis: This condition can manifest as painless nodules on the skin, including the legs, and can recur over time. It is often associated with systemic symptoms such as fever, fatigue, and weight loss.
- Panniculitis: This is an inflammation of the subcutaneous fat, which can present as painless nodules on the legs. It can be caused by a variety of factors, including trauma, infection, or autoimmune disorders.
Do Not Miss Diagnoses
- Subcutaneous panniculitis-like T-cell lymphoma: This is a rare and aggressive form of lymphoma that can present with painless nodules on the skin, including the legs. It is often associated with systemic symptoms such as fever, fatigue, and weight loss.
- Deep vein thrombosis: Although less likely, deep vein thrombosis can present with painless nodules or swelling on the legs, and is a potentially life-threatening condition if left untreated.
- Kaposi's sarcoma: This is a rare cancer that can present with painless nodules on the skin, including the legs, and is often associated with immunosuppression or HIV infection.
Rare Diagnoses
- Necrobiosis lipoidica: This is a rare condition that presents with painless nodules on the skin, often on the legs, and is associated with diabetes mellitus.
- Granuloma annulare: This is a rare condition that presents with painless nodules on the skin, often on the legs, and is associated with diabetes mellitus or thyroid disease.
- Rheumatoid nodules: These are rare, painless nodules that can occur on the skin, including the legs, in patients with rheumatoid arthritis.