Introduction
Folliculitis describes an inflammation of the hair follicles, also known as hair follicles. It can be both acute and chronic. A folliculitis can also be non-purulent or accompanied by pus formation.
Triggering factors for folliculitis are often infections with bacteria, fungi or parasites. An immune deficiency or medication can also cause folliculitis. Particularly predisposed areas of the folliculitis are hairy parts of the body such as the head or buttocks. Increased sweating in these regions in particular increases the risk of folliculitis.
Causes
Folliculitis is caused by various factors. These causes can be roughly divided into infectious and non-infectious causes. These two large groups can in turn be divided into several subgroups.
The infectious causes of folliculitis are primarily bacteria. Especially the bacterium Staphylococcus aureus plays a decisive role here. This bacterium typically occurs as part of the normal skin flora.
If the skin is injured or the immune system is weakened, this can lead to an inflammation of the hair follicle. Another possible infectious cause of folliculitis is a colonization with fungi, the so-called dermatophytes. Viruses, such as the herpes simplex virus, are also possible causes of folliculitis.
Parasites, especially certain types of mites, can also cause infectious folliculitis. Causes of a non-infectious folliculitis can be, for example, numerous medications. These include steroids and so-called thyrosine kinase inhibitors, which can be used in cancer therapy.
Hair growth disorders or disorders of skin hornification can also be considered as causes of folliculitis. A congenital immunodeficiency or an immunodeficiency caused by the intake of immunosuppressive drugs can also be the cause of folliculitis. In addition, chronic diseases such as diabetes mellitus can cause folliculitis. In some forms of folliculitis the cause is not yet known.
Symptoms
As with all inflammations, folliculitis also causes the classic inflammatory symptoms. These inflammatory symptoms present themselves as redness, swelling and overheating of the affected region. Folliculitis can also be very painful.
In some cases, an unpleasant itching develops on the inflamed hair follicles. The affected patient may see small papules or pustules in the inflamed area. These often present in the middle of the pustules with a single hair, which is very typical for this disease, because finally the hair follicle is affected in folliculitis.
Typical locations for the occurrence of folliculitis are hairy areas of the body such as the head, beard and also the buttocks. Typical symptoms of folliculitis often occur when the affected region has been shaved beforehand. The smallest skin lesions give pathogens the chance to penetrate the skin and cause inflammation.
Some forms of folliculitis not only lead to hair follicle inflammation. In the course of the so-called folliculitis declavans, there is first an inflammation, in the course of the disease a crust formation and finally a scarred healing, which causes hairless areas. In the case of a skin fungus infestation, additional scales can form in the inflamed area.
These scales occur mainly at the edge of the inflamed areas. The folliculitis is the preliminary stage of a furuncle. The terms “abscess” and “boil” are often used as synonyms. But there are some clear distinguishing features.
