Sebum
Tallow is a specific fat that is produced by the body to protect the hair. For this purpose the sebum is secreted by the valley glands at the hair roots. These sebaceous glands can easily become clogged, which leads to an increased accumulation of sebum.
This accumulation can, if it is large enough, make a bulge under the skin. If the sebaceous gland is additionally infected by bacteria on the skin, a small inflammation will occur. The sebaceous gland swells, resulting in a large, red and painful lump. Usually both the infected and the congested sebaceous gland disappear on their own within a few days.
Dent under the skin after vaccination
Immediately after a vaccination, the dent under the skin can be caused by the vaccine itself. The vaccine is then usually absorbed by the tissue within a few minutes, so that the vaccine dent disappears. A vaccine is always an incentive for the immune system to fight the substance.
Only in this way can the immune cells get to know the attenuated pathogen and form specific antibodies. This means that the immune system is best equipped when it encounters the actual pathogen and can thus fend it off effectively. After a vaccination there is a lot of the vaccine at the injection site.
The body therefore reacts not only systemically but also at the site of vaccination. This is where a particularly large number of immune cells are sent, which can lead to local inflammation. This impresses as a bump under the skin.
Associated symptoms
The accompanying symptoms of a lump under the skin are highly dependent on what the cause of the lump is. If a bump is caused, for example, by bumping the forehead, there is usually additional pain in the area. Headaches are also possible.
It can also bleed into the bump if the impact was strong enough to burst a small blood vessel. This usually causes an additional bruise. Bumps that are caused by infections, for example an infected congested sebaceous gland or an abscess that has developed from it, are usually painful.
The inflammation also leads to redness and overheating of the affected area. Tumours that cause a bulge under the skin usually cause no or only very unspecific symptoms. Benign tumours can press locally on structures under the skin, for example on nerves or blood vessels and thus cause reduced skin circulation or discomfort, but they are usually only aesthetically disturbing.
Malignant tumours can be painful or even itchy; if they have been growing for a long time, they can also affect the entire body. Increased fatigue occurs, night sweats, fever and weight loss are also possible. A lump under the skin can quickly cause pain.
This is either due to the cause of the lump, as it happens for example when you bump into a body part. But also infectious causes of a bump, which lead to local inflammation of the skin, usually cause local pain. Bumps, which are particularly large, can press on small nerve branches under the skin and also cause pain there due to irritation.
