Sebaceous glands are almost all over the body. The androgens (sex hormones) are responsible for stimulates sebum production. Even though many people may initially have unpleasant associations with the word “sebaceous glands” such as oily or greasy – sebaceous glands are by no means superfluous. They have important functions, such as protecting our skin from drying out. But what happens when diseases of the sebaceous glands occur, for example, because they are blocked or inflamed? We clarify.
Sebaceous glands – overview
Structure and function of sebaceous glands
Sebaceous glands are exocrine glands, which means that they release their secretion to the outside. They are located under the epidermis (dermis) and mostly flow into the coat of the hair (hair follicle).
How does sebum get from the sebaceous cells to the surface of the skin?
The sebaceous gland cells store fat droplets as they mature – until the cells are well filled. In a further step, the cells dissolve and the contents are emptied into the ducts through which the secretion produced by the sebaceous glands leaves the glandular tissue. When it reaches the surface of the skin, a thin layer of fat is formed, which protects the skin from the sebum glands.
- the dehydration,
- Skin diseases,
- pathogens and
- chemicals protect and make the skin supple and stable and hair shiny.
Seven days pass – from the bursting of the full sebaceous gland cell until the sebum reaches the surface of the skin. If the previous sebum production is taken into account, it even takes four weeks from the first hormone signal to the sebaceous gland to excretion.
Did you know that the densest area per square centimeter of sebaceous hair follicles is the scalp: There are 900 of them. Second place goes to the forehead with 400, third place to the back with 160 and fourth place to the arms and legs with less than 501. On average, a young adult produces about 2 grams of sebum daily2. With increasing age, the activity of the sebaceous glands gradually decreases, which is why the skin tends to become drier with age.
How much sebum does the body produce?
Sebum production depends on the size and activity of the sebaceous glands and can fluctuate for individual, age-related or regional reasons: The number and arrangement of hair and sebaceous glands varies greatly depending on the region of the body. The strongest regulating factor is androgens, which are male sex hormones. They ensure that the sebaceous glands grow and that increased sebum production takes place.
How does sebum production change in the course of life? One thing first – there is quite a lot of up and down: after birth, the activity of the sebaceous glands is very high, it then drops rapidly in infancy, increases significantly again due to the increased release of androgens in puberty and continues to decline with increasing age. The skin becomes drier and drier until sebum production comes to an almost complete standstill in old age.
Are there also sebaceous glands that have no connection to hair?
Yes, there are isolated, so-called “free” sebaceous glands which occur wherever the skin merges into mucous membrane, for example on eyelids and lips (ectopic sebaceous glands). The sebaceous glands are completely missing only on the palms of the hands, the soles of the feet and on the balls of the fingers and toes.
Diseased sebaceous glands – how it comes about and what people affected can do about it
Diseases of the sebaceous glands are usually limited to regions with sebaceous follicles (face, trunk).
Acne vulgaris – one of the most common dermatological diseases
Excessive sebum production (seborrhoea) is a typical symptom of the most common form of acne, acne vulgaris. It is caused by the closure of the hair follicles and the subsequent inflammations – e.g. those caused by bacterial colonization – and is characterized by blackheads, papules (nodules) or pustules. Even though acne can occur in newborns as well as in older adults, it usually plagues people in adolescence and almost everyone is affected at this age.
There are different courses of skin disease:
In 60 percent of cases, the skin disease is mild and acne can be controlled without medical treatment (acne vulgaris grade I-II).
In the other 40 percent, the disease is acute to chronic, the sebaceous glands are highly inflamed, which ultimately leads to severe scarring of the skin and can be psychologically very stressful for those affected (higher degrees of severity III and IV as well as acne conglobata, a severe form of acne vulgaris).
Severe forms of acne are often hereditary and boys are more frequently affected.
Depending on the severity there are different therapy options:
- Comedolytic therapy: Vitamin A acid is applied to the affected skin areas. This counteracts the cornification in the glandular duct, dissolves existing corneal plugs – so that the accumulated sebum can be removed – and also prevents the formation of new blackheads.
- Isotretinoin: The active pharmaceutical ingredient is used primarily for severe acne. It is a synthetic retinoid (chemical substance) that has a similar chemical structure to retinol, vitamin A. It is used to treat severe acne. The administration of isotretinoin causes the sebaceous glands to recede reversibly and the acne vulgaris can heal.
- Antibacterial therapy: The sole therapy with antibiotics such as erythromycin, clindamycin, tetracycline or minocycline does not make sense; it should always be accompanied by comedolytic (blackhead-dissolving) treatment. But beware: Isotretinoin and tetracycline must not be administered together, as there is a risk of increased cerebral pressure (pseudotumor cerebri).
- Oral contraceptives (contraceptive pill): Acne can be improved by their antiandrogenic effect.
What does not help with acne vulgaris are diets, local disinfection and superficial removal of skin fat and germs using soaps, UV radiation, and chemical peelings.
All of the above therapy options can have side effects, such as skin irritation, increased UV sensitivity, dehydration of skin and mucous membranes, headaches, liver function, and fat metabolism disorders or a paradoxical worsening of acne with fever. Have your dermatologist inform you in detail about possible side effects and advise you which treatment method is best suited to your individual case.
Perioral dermatitis – the “mannequin disease
Anyone suffering from perioral dermatitis has to cope with the consequences of skin irritations on the face:
- The skin tightens, burns and inflammatory nodules and pustules form.
- Typical are also reddening of the skin around the eyelids, corners of the eyes and cheeks.
- Red spots also appear in the area of the mouth, only a hem directly around the lips is spared.
The reason for this skin disease is in most cases the excessive use of make-up and skin care products – hence the term “mannequin disease” or “stewardess disease”. Predominantly women between the ages of 16 and 45 are affected by this stressful, though not an infectious skin disease. In Germany, about six percent suffer from this disease.5
Excessive skin care, i.e. the use of excessive amounts of moisturizers and the like, can over-moisten the skin. Too much care products lead to the fact that
- the follicles in the face swell up,
- the bacteria in the follicles multiply,
- and eventually, lead to inflamed sebaceous glands.
Creams containing cortisone as a treatment method are usually counterproductive. Although they fight the inflammation at first, the symptoms worsen after weaning. It is best to wean the skin from the previously used day, night and anti-wrinkle creams. The article “Perioral Dermatitis” tells you which treatment options and household remedies are still available.
Can sebaceous glands be removed?
Clogged sebaceous glands can swell so much that so-called sebaceous cysts, which can even reach the size of a mandarin. Ideally, sebaceous cysts are surgically removed before an infection develops. To prevent the sebaceous glands from swelling again, the entire sebaceous cyst is removed. At this point, health insurance companies only cover the costs of medically necessary interventions. As soon as purely cosmetic reasons come to the fore, those affected have to bear the costs themselves.
Care for every skin type
How do you care for your skin properly when you should not overdo it with skin care? First and foremost is the thorough cleansing of the skin to rid it of dirt, sweat, sebum, and make-up.
Tips for different skin types:
- Oily skin: If the skin is oily, the sebaceous glands produce too much skin fat (seborrhoea). Moisturizing and slightly dehydrating products help here.
- Dry skin: Especially with increasing age, the skin cells do not renew so quickly, the sebaceous glands produce less fat (sebostasis). Anyone who leads under dry and sensitive skin should rather use oily products.
The skin is our largest organ in terms of area. It plays an active part in protecting the skin and caring for it properly. Further skin care tips that are independent of skin type can be found here.