Differential Diagnosis for a Knot Above the Ear
- Single most likely diagnosis
- Epidermal cyst (sebaceous cyst): A common, benign cyst that can form on the skin, including the scalp, and may present as a knot or lump.
- Other Likely diagnoses
- Folliculitis: An inflammation of the hair follicles, which can cause redness, swelling, and knots or bumps on the scalp.
- Furuncle (boil) or carbuncle: A bacterial infection of the skin and subcutaneous tissue, which can cause a painful knot or lump.
- Abscess: A collection of pus that can form on the skin, including the scalp, and may present as a painful knot or lump.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningioma: A rare, usually benign tumor that arises from the meninges, which can cause a lump or knot on the scalp, and may be life-threatening if not diagnosed and treated.
- Osteoma: A rare, benign tumor of the bone, which can cause a hard, fixed knot or lump on the scalp.
- Metastatic tumor: A rare, but potentially life-threatening condition, where cancer from another part of the body spreads to the scalp, causing a knot or lump.
- Rare diagnoses
- Dermatofibroma: A rare, benign skin growth that can cause a firm, knot-like lump on the scalp.
- Pilomatrixoma: A rare, benign tumor of the hair follicle, which can cause a firm, knot-like lump on the scalp.
- Neurofibroma: A rare, benign tumor of the nerve tissue, which can cause a knot or lump on the scalp, and may be associated with neurofibromatosis type 1.