An overview of human skin diseases

What most people are not even aware of: The skin is the largest organ in the human body and is an organ with many different functions.

The skin is the body's first barrier against harmful external influences, be it viruses and bacteria, toxins or mechanical trauma such as sharp objects. It protects us against heat loss or overheating and serves to absorb sensory stimuli. In addition, it serves the exchange of substances: gases and liquids are released, many substances are absorbed through the skin and mucous membrane.

The structure of the outer skin is divided into three layers:

  • Epidermis (Epidermis), serves as a mechanical barrier,
  • Dermis (Dermis), anchors and nourishes the epidermis,
  • Subcutis (Subcutaneous tissue), here are larger blood vessels, nerves and the sensory cells of the skin for tactile, pain and vibration sensations etc.

Furthermore, the skin appendages such as hair, nails and sweat glands belong to the skin.

Classification of skin diseases

  1. Infectious skin diseases
  2. Fungal diseases
  3. Tissue-specific diseases
  4. Tumor Diseases
  5. Genetic diseases
  6. Autoimmune diseases
  7. Skin diseases of unknown origin
  8. Granulomatous skin diseases

Infectious skin diseases


Herpes viruses lead to an infectious disease with preferential infestation of the skin and the mucous membrane. They linger in human tissue and are reactivated when the immune system is weakened.
The best known is the herpes simplex virus, which can be divided into type 1 and type 2. Type 1 causes the infection on the face, often on the lips. Type 2, on the other hand, causes an infection in the genital area.
The weakened immune system should first recover. If the course is severe, drug therapy with acyclovir can be sought.

More on the subject here Herpes read up.


The clinical picture phlegmon describes an inflammation of the soft tissue. This can fester and be painful in the course.
It is triggered by bacteria such as streptococci or staphylococci.
Phlegmon should definitely be treated, as in the worst case it can lead to blood poisoning. High-dose antibiotics are used for this.
If the patient goes to the hospital on time and receives adequate therapy, the prognosis is very good.

Find out more about the topic here: Phlegmon.


Scabies describes a skin disease that is caused by certain parasites (so-called itch mites). It is a highly infectious disease that usually occurs in places with poor hygiene.
Those affected complain of itching, rashes and flaking. The scabies can be treated very well with medication (so-called anti-itch preparations).

Read more about the topic here: Scabies.


Parasites are small living things that attack other living things in order to feed themselves. They settle in different areas of the body. For example, these can occur on the skin and hair.
The most common causes of transmission are poor hygiene and the associated contaminated food and drinking water.
Depending on the place of settlement, very different symptoms can occur. If the skin is affected, severe itching and redness occur.

You can find out more about this topic here: Parasites of humans.

Fungal diseases

Skin fungus

The skin fungus can manifest itself in many different parts of the human body. The affected areas are marked by reddening of the skin surface and severe itching. Scaly plaques form and the skin can tear, causing wounds.
For therapy, ointments can be used that contain the active ingredients that kill the pathogens.

More on the subject here Fungal diseases read up.

Athlete's foot

Athlete's foot is one of the most common skin diseases in Germany. The affected areas show reddening. In addition, there is severe itching and flaking of the skin in these areas. Oozing of the skin and the formation of blisters is also possible.
The risk of infection is high in public pools.
Various creams are available for therapy, as well as drugs that are supposed to kill the fungi.

Find out more about the topic here: Athlete's foot.

Nail fungus

An infection by a nail fungus describes the infestation of the nail bed. The nail is thickened and deformed, which leads to instability. As a result, the nail begins to crumble. In addition, there is a yellowish, brown discoloration. It can also cause pain when walking.
The risk of infection is particularly high in warm, humid environments, such as high in the sauna or swimming pool.
In the case of a slight infestation, conventional home remedies such as apple cider vinegar and baking powder are a good alternative to medication. If the nail bed is infested, medication can be taken that kill the fungi.

You can find out more about this topic here: Nail fungus.

Tissue-specific diseases

Acne (acne vulgaris)

The most common skin disease is acne. It typically begins in puberty between the ages of 10 and 14 and regresses by the age of 20-25 at the latest.
Depending on the severity, the clinical picture is characterized by comedones (blackheads), papules and pustules (pimples) and abscesses (pus formations). Most affected areas are the face, shoulders, and a V-shaped area on the upper back and chest.
Acne vulgaris is an inflammatory disease of the sebum glands, which is triggered by various factors (e.g. bacteria).
The basis of the treatment is correct and thorough skin cleansing. Depending on the extent, other therapy options, such as the administration of antibiotics, can also be considered.

Find out more about the topic here Acne.


The clinical picture of hyperkeratosis describes thickening of the outer skin layer, so-called horny layer. Usually it has a protective role. However, various causes can lead to a disorder and thus increased formation of the cornea.
Hyperkeratosis comes in various forms, such as wart, corn or actinic keratosis.
Causes for the development can be mechanical irritation or UV radiation.
The therapy depends on the type of hyperkeratosis.

Read more about the topic here: Hyperkeratosis.


Leukoplakia describes the thickening of the cornea of ​​the mucous membranes (especially in the mouth area). It forms white streaks that cannot be wiped off.
The risk that a skin tumor will develop from such a skin change is increased.
The cause of the development is mechanical irritation. There are no symptoms other than the whitish appearance.
The therapy includes consistent avoidance of irritation. For example, patients who smoke should stop immediately. The leukoplakia then usually heals on its own.

You can find out more about this topic here: Leukoplakia - What are the Dangers?

Sebum cysts

Sebaceous gland cysts are caused by a blockage of a sebum gland with sebum secretions. In medical terminology, it is also known as atheroma. They can occur in different parts of the body, such as on the head or in the genital area.
An exact cause for the development is not known.
Sebaceous cysts are usually asymptomatic. They cause pain in rare cases. For example, if they become infected due to a bacterial infection.
Therapy consists of removing this cyst.

Find out more about the topic here: Sebum cysts.


A mole (Latin: nevus) describes a malformation of the skin that occurs due to an increase in pigment cells in a locally limited area. It is one of the most common skin changes. In principle, they all represent the precursors of skin cancer, but the degeneration rarely occurs.
If the liver spots are noticeable, tissue samples are taken and the dermatologist decides whether the removal makes sense.

More on the subject here Moles read up.

Tumor Diseases

Skin cancer: basalioma

A basalioma describes a specific type of skin cancer. This tumor originates from the so-called basal cells of the epidermis (epidermis) out. This tumor rarely forms metastases (daughter tumors), which is why it is medically classified as semi-malignant, i.e. semi-malignant. Basaliomas occur in most cases on the face. Risk factors for the development are intense solar radiation and chemical pollutants such as arsenic.
Typical are a pearl-like edge wall and the small vessels that grow into the tumor (Telangiectasia).
A basalioma can be treated well by means of an operation or radiation.

Find out more about the topic here: Basalioma.

Skin cancer: spinalioma

A spinalioma is a malignant degeneration of the cells on the surface of the skin with uncontrolled growth. The tumor does not spread in depth but in width and is therefore also referred to as a horizontally growing tumor. Metastasis is rare. The main risk factor for the development of a basalioma is chronic sun rays.
There are numerous therapy options available. For example, the tumor can be irradiated. However, surgical resection is preferred in most cases.

Read more on the topic Spinalioma.

Skin cancer: melanoma

Malignant melanoma describes a highly malignant tumor that is caused by the pigment cells (Melanocytes) the skin runs out. Melanomas quickly metastasize to other organs through the lymphatic system and blood.
Risk factors for the development are liver spots, severe sunburn and also genetic factors. '
The prognosis of this tumor depends on the stage (stage I-IV) and the metastases. The most important therapeutic measure is the surgical removal of the melanoma with a certain safety margin.

Find out more about the topic here: Malignant melanoma.

The lipoma

A lipoma is a resilient lump that lies under the skin. This is a benign growth that arises from fat cells in the subcutaneous fatty tissue. As a rule, they do not cause any discomfort.
Lipomas can appear in a variety of locations, such as the back or chest. Exact causes are not yet known. A genetic disposition is assumed.
Therapy consists of surgical removal of the lipoma.

Find out more about the topic here: Lipoma.

Genetic skin diseases


Psoriasis (Latin psoriasis) is a chronic, inflammatory disease. The skin cells migrate through the individual skin layers much faster than normal. Typical sites of predilection are the scalp, the extensor surfaces of the arms and legs, the belly buttons and the anal folds.
The cause for the development of this clinical picture is a certain genetic disposition (antigen HLA-1 and HLA-2) and external environmental factors.
Therapy consists of skin care with various ointments, such as an ointment with salicylic acid. In addition, ointments containing glucocorticoid (cortisone) can be used in psoriasis attacks.

You can read more about this topic here: Psoriasis.


The term albinism is derived from the Latin word for white, "albus“, From. Those affected suffer from a pigment deficiency, which is noticeable by very light skin and hair color.
The cause of this disease is a mutation in the genes that code for the color pigment melanin.
The risk of sunburn and skin cancer is increased.
The therapy of the present genetic defect is unfortunately not yet possible. For this reason, these patients should pay particular attention to UV protection.

Read more on the subject here Albinism - what is it?

Xeroderma pigmentosum

This disease is a genetic defect in the DNA repair enzymes. As a result, the damage to the DNA caused by UV rays can no longer be repaired. This leads to an increased sensitivity to light (Photosensitivity), premature skin aging and an increased risk of skin cancer.
There is currently no therapy for this genetic defect. Affected patients should avoid UV rays and be checked regularly for skin changes.

You can find out more about this topic here: Xeroderma pigmentosum.

Neurocutaneous melanosis

Neurocutaneous melanosis describes a rare skin disease that can also affect parts of the brain and the spinal cord.
The exact causes of this disease are not yet fully understood.
Those affected have large moles all over their bodies. The diameter of these moles can be up to 40cm. They arise from accumulations of melanocytes (pigment-forming cells in the skin).
There is no specific therapy. Patients should have the liver spots checked regularly by the dermatologist, as these have an increased risk of developing cancer cells.

You can find more information on this topic here: Neurocutaneous melanosis.

Autoimmune skin diseases

Lupus erythematosus

The clinical picture of lupus erythematosus describes a systemic disease of the skin and connective tissue. It is an autoimmune disease from the group of collagenoses.
Those affected complain of fever, weakness and pain in the joints. In the majority of patients, the skin is also involved, which manifests itself in the form of rashes. But other organs can also be affected.
The cause of the development is still unknown today. Unfortunately, there is also no specific therapy.

Read on here: Lupus erythematosus.


Scleroderma describes an inflammatory rheumatic disease of the skin. It is an autoimmune disease from the group of collagenoses. Collagen is deposited in the small blood vessels and in the connective tissue. This hardens the skin over time.
The exact cause of the development has not yet been clarified. There is no specific therapy. The most common drugs used are D-penicillamine or glucocorticoids.

You can find out more about this topic here: Scleroderma.

Skin diseases of unknown origin


Neurodermatitis, also called atopic dermatitis, is an inflammatory disease of the skin. It is a chronic disease that occurs permanently or in a chronically recurrent form. Those affected suffer from severe itching and dehydration of the skin. In addition, there are redness, blisters, poplars and flaking in these areas.
The exact causes of this disease have not yet been clarified.
The basic therapy for every patient is sufficient oiling of the skin in order to rebuild the barrier function and prevent dehydration. Depending on the course, glucocorticoids or drugs that model the immune system are also used.

Read more on the subject here Neurodermatitis.


The disease rosacea describes a chronic inflammation of the facial skin. Symptoms of rosacea include redness and the formation of veins. In more severe cases, inflammatory papules and pustules can also occur. Rosacea can also manifest itself in the eyes.
The cause of the development has not yet been fully clarified. Therapy consists in alleviating the symptoms, for example through local and systemic drug treatment.

You can find more information on this topic here: Rosacea - Why Is It?

Lichen Ruber Planus

The clinical picture of lichen planus, also known as lichen planus, describes a chronic inflammatory disease of the skin and mucous membranes that is relapsing. This creates itchy nodules in different parts of the body. In addition to the brown discoloration, the affected areas may also have fine milky-white stripes (Wickham Stripe) exhibit.
If the mucous membrane is infected, white, net-like deposits are found.
Unfortunately, the causes are not entirely clear. Therapy consists of local treatment with ointments containing cortisone. Alternatively, severely keratinized lesions can be treated with salicylic acid or irradiation with UV light.

Find out more about the topic here: Lichen Ruber.

Granulomatous skin diseases

The granuloma

The term granuloma comes from the Latin and means "nodule". It describes an inflammatory reaction. They can be found in different parts of the body.
The causes are very diverse. Possible causes can be tuberculosis, sarcoid or Crohn's disease. The symptoms are very individual and depend on the location of the granulomas.
There is no uniform therapy for granulomas. Medicinal and surgical measures are an important basis for this.

Find out more about the topic here Granulomas.