A lump or “ball” discovered behind the ear, an area containing lymph nodes and glands, can cause concern. While most lumps in this region are benign and related to minor, temporary conditions, it is important to understand the potential causes. This information is for general knowledge and should not replace a professional medical examination for an accurate diagnosis.
Infection Related Swelling
The most frequent cause of a ball behind the ear is the swelling of lymph nodes, medically termed lymphadenopathy. Lymph nodes are small, bean-shaped components of the immune system located in this area. Their function is to filter lymph fluid, trapping viruses, bacteria, and cellular debris. When the body detects an infection, these nodes enlarge as they produce white blood cells.
This localized swelling is a direct immune response, indicating the body is actively fighting an illness. Common infections that trigger this reaction include ear infections (like otitis media), scalp infections (such as dermatitis or fungal infections), upper respiratory infections, strep throat, or dental abscesses.
A lump caused by a reactive lymph node typically feels soft, rubbery, and mobile, moving easily beneath the skin when pressed. It is often painful or tender to the touch, especially during the peak of the underlying infection. Once the infection clears, the swelling gradually subsides, usually returning to normal within a few weeks.
Benign Growths of the Skin and Soft Tissue
Lumps not related to systemic infection often originate from the skin or underlying soft tissues. These benign growths develop slowly and present differently than the rapid, tender swelling of lymph nodes. Common types behind the ear include sebaceous cysts and lipomas.
A sebaceous cyst (or epidermoid cyst) forms when a hair follicle or oil gland becomes blocked, trapping dead skin cells and keratin. These growths feel smooth and firm, resisting movement under the skin. They are typically painless unless infected, which causes redness, inflammation, and tenderness, sometimes leading to an abscess.
In contrast, a lipoma is a benign growth composed of mature fatty tissue beneath the skin. A lipoma is characterized by a soft, doughy, or rubbery texture and is easily movable with slight finger pressure. These growths are almost always painless, grow very slowly, and are less likely to become infected than sebaceous cysts.
Structural and Glandular Causes
Less common causes involve inflammation or infection of deeper structural components, such as the bone or salivary glands. These conditions present with specific and sometimes more severe associated symptoms. The mastoid bone, located just behind the ear, contains air cells.
Mastoiditis occurs when an untreated middle ear infection spreads to the air cells within the mastoid bone, causing a serious bacterial infection. The resulting lump is a painful, reddish, and doughy swelling that may push the ear outward. This condition is usually accompanied by systemic symptoms, including high temperature, significant ear pain, and fluid drainage from the ear canal.
The parotid gland, the largest salivary gland, is situated near the ear and jawline. Swelling of this gland, known as parotitis, can be caused by viral infections (like mumps), bacterial infections, or the blockage of a salivary duct by a stone. This glandular swelling typically presents as a painful lump accompanied by discomfort or pain when chewing, sometimes with a fever.
Signs That Require Immediate Medical Attention
Although most lumps behind the ear are benign, certain characteristics require immediate medical attention. Any lump rapidly increasing in size should be examined without delay. Lumps that are hard, irregular in shape, or fixed and immovable warrant immediate medical assessment.
A persistent lump that does not begin to shrink within two or three weeks after a suspected infection has cleared should be reviewed by a clinician. Other concerning symptoms include:
- Unexplained weight loss
- Persistent fever
- Night sweats
- Difficulty swallowing or breathing
- Drainage, an open sore, or a change in the overlying skin texture