A bump on the head is a common occurrence. These lumps vary widely in appearance and texture, from small, tender pimple-like spots to large, firm masses under the skin. Understanding their origins helps distinguish between minor, temporary issues and those that may require medical attention. Causes of head bumps include superficial skin irritation, structural growths, or external impact.
Inflammatory Skin Conditions of the Scalp
Many common head bumps originate in the skin or hair follicles, resulting from inflammation or infection. These issues are often superficial, located on the outer layer of the scalp, and are frequently tender or itchy. The scalp is dense with hair follicles and sebaceous glands, making it susceptible to these issues.
Folliculitis, often described as scalp acne, occurs when hair follicles become inflamed, usually due to a bacterial or fungal infection. This condition presents as small, red bumps that frequently have a pus-filled white head, similar to a pimple. These lesions can be painful or itchy and typically appear scattered across the scalp where hair grows.
Seborrheic dermatitis is a more severe form of dandruff. It manifests as red, greasy patches covered with yellowish scales that can sometimes build up into small bumps. The inflammation is often linked to an overgrowth of the Malassezia yeast. This condition is most common in areas rich in sebaceous glands, such as the hairline and behind the ears.
Contact dermatitis is an inflammatory reaction that occurs after the scalp touches an irritating substance or an allergen. This can result from chemicals in hair dyes, shampoos, or other styling products. The bumps associated with this reaction are typically red, intensely itchy, and may sometimes progress to weeping or crusting. Identifying and avoiding the trigger substance is the primary way to manage this kind of inflammation.
Benign Growths and Subcutaneous Lumps
Bumps that feel firm, fixed, or slow-growing often originate beneath the skin’s surface or from the underlying bone structure. These masses are typically non-inflammatory and do not involve redness or pus, distinguishing them from superficial skin conditions. Most of these structural lumps are benign.
Pilar cysts are the most common type of cyst found on the scalp. They form from the root sheath of the hair follicle and are filled with keratin, a protein found in hair and nails. These cysts present as smooth, firm, dome-shaped lumps that are often movable under the skin and can range in size.
Lipomas are non-cancerous tumors composed of mature fat cells that grow just below the skin in the subcutaneous tissue. A lipoma on the head generally feels soft and doughy and moves easily when pressed with a finger. They grow very slowly over months or years and are usually painless unless they grow large enough to compress a nearby nerve.
Osteomas are hard, bony growths that form on the skull itself, usually arising from the outer layer of the bone. Unlike cysts or lipomas, an osteoma feels rigid and fixed because it is attached directly to the underlying bone. These bone tumors are benign, slow-growing, and frequently cause no symptoms unless they are located near sensitive structures like a sinus cavity.
Bumps Caused by Injury or Acute Trauma
Bumps caused by injury appear rapidly following a physical impact or external trauma. The scalp is highly vascular, which causes swelling to occur quickly after a blow.
The resulting lump is medically termed a hematoma, commonly known as a “goose egg” on the scalp. A hematoma forms when blood vessels are damaged by the impact, causing blood to pool and clot beneath the skin. This lump is soft to firm initially and can be quite tender immediately after the injury.
The size of the bump is not always indicative of the severity of the underlying injury. For minor trauma, the body naturally reabsorbs the pooled blood over time, and the hematoma typically resolves within two to four weeks. Scalp contusions, or bruises, are a milder form of trauma where damage to the capillaries causes discoloration without the significant lump formation seen in a hematoma.
When to Consult a Doctor and Home Management
While many head bumps are harmless and resolve without intervention, certain symptoms warrant a medical evaluation to rule out more serious conditions. Any bump that increases rapidly in size over a few weeks or changes significantly in color or texture should be examined. Lumps that bleed, ooze, develop irregular borders, or feel hard and fixed, require prompt medical attention.
For bumps resulting from trauma, seek immediate emergency care if the injury is accompanied by signs of a possible concussion. These signs include:
- A persistent or worsening headache
- Repeated vomiting
- Loss of consciousness
- Confusion
- Slurred speech
- Difficulty with balance
Any bump that appears after an injury and is coupled with a fever or unusual neurological symptoms needs urgent medical assessment.
For minor bumps related to inflammation or small, slow-growing masses, general home management can provide relief. Avoid picking, squeezing, or attempting to drain any bumps, as this can introduce bacteria and lead to infection or scarring. Gentle cleansing of the scalp with a mild shampoo can help manage surface conditions like folliculitis or seborrheic dermatitis. Over-the-counter anti-inflammatory medications can reduce pain and swelling for minor traumatic bumps.