Lesions of the skin

Skin lesions include any abnormality that shows up on the skin, from a small abrasion to a deep wound.


Classification of skin lesions

The elemental violations are divided into:

  • primary or original lesions, if they are the result of pathological skin inflammation;
  • secondary lesions, if they have arisen from a primary injury;

Primary skin lesions

Systemicskin lesions include:

Bubbles – small elevations filled with clear liquid.
Bubbles can be a consequence of:

Maculae are small brown, red or white spots. The coloration depends on the amount of melanin.
Bright spots include:

  • pale birthmarks (nevi),
  • white spot disease (vitiligo),
  • Pityriasis alba.

Dark spots include:

  • Freckles (Ephelides),
  • moles (lentigines),
  • Moles (nevi).

nodule is a solid neoplasm in the skin:

  • sublime
  • with a diameter greater than 1 cm,
  • at the level of the dermis and subcutaneous tissue.

The papule is a superficial structure, smaller than 1 cm, caused by:

  • a thickening of the epidermis (epidermis),
  • Accumulation of inflammatory fluid in the dermis (dermis).

Most papules develop grape-shaped and there is a rash.
Some typical papules are caused by:

  • Insect
  • exanthematic diseases (e.g. measles).

Plaques are solid superficial structures.
Papules that develop as a group can form plaques.
The plaques often occur in people with psoriasis.

Pustules are small lesions filled with pus.
In general, they are a consequence of:

Primary skin lesions caused by allergic reactions

Rashes are lesions that cover small or large areas of skin.
They can be caused by an allergic reaction.
Urticaria is a reaction of the skin that occurs when one comes into contact with a substance (food, plants, metals, etc.) that triggers an allergic reaction.
Typical skin lesions caused by allergic reactions are:

Wheal are skin lesions caused by an allergic reaction. A wheals is a firm, reddened elevation of the skin that causes severe itching. As a rule, it passes again in a short time.
A wheal is a typical injury of urticaria.

Erythema is an irritated and reddened area of skin. Erythematous lesions can have irregular margins and varying forms of spread.

Secondary skin lesions

  1. The crust develops from a skin injury.
  2. Excoriation is a skin lesion caused by scratching, which can result from friction against a rough surface or from an itchy disease such as scabies.
  3. Erosion is caused by the loss of epidermal cells and can develop from a vesicle or bubble after they burst.
  4. The rhagade is an elongated wound that reaches deep into the skin.
    If it bleeds, it leaves scars, such as rhagades.
  5. Ulceration is an injury to the tissue that can spread to the depths and then usually proceeds chronically.
    For example, one can observe varicose ulcers caused by:

  6. The scar is formed by fibrous connective tissue and is the result of repair processes after an acute wound or ulceration.

Causes of skin lesions

Injuries on the skin can result from various skin disorders.
Among them are:

Physical disorders
Allergies to foods/substances. Common allergens include:

  • Milk
  • Eggs
  • Pollen
  • Grass.

Skin diseases such as:

Skin injuries caused by AIDS
Skin injuries can be caused by diseases such as AIDS.
The acquired immunodeficiency or AIDS is caused by the HIV virus, which weakens the body’s immune system.
Patients with AIDS often develop lesions because their bodies are unable to resist or fight the virus.

Allergies and allergic reactions
Skin rashes are observed mainly due to allergies to certain substances, chemical products, cosmetics, etc. Sometimes this can happen as a result of an overdose of drugs or their incorrect intake, for example hydroxyurea (Siklos®), which can cause redness and atrophy of the skin.

Cutaneous leishmaniasis The most common form of leishmaniasis
causes one or more sores on the skin. Initially, the skin damage consists of a small red plaque, reaching up to 2 cm in diameter. It looks like an ordinary insect bite.
After a few weeks, the plaque becomes darker and forms ulcers with:

  • raised edges,
  • central dents.

The ulcers may be moist and secrete pus or they may be dry and form a crust.
The wounds appear only on the exposed skin, especially:

  • facial
  • on the extremities.

The lesions may arise immediately after the bite of an infected sandfly, or they may cause sores after an incubation period of weeks to months.

Lyme disease Lyme disease
is a bacterial infection caused by spirochetes: Borrelia burgdorferi.
This disease is transmitted by tick bite.
Lyme disease causes redness, which can spread up to half a meter; for this reason, it is also referred to as erythema migrans.
The skin lesion is flat and darker in color at its edges.

Behçet syndrome
Skin problems are a common symptom of Behçet’s disease.
The symptoms of skin disease caused by Behçet’s disease are different; red nodules or pus vesicles (pustules) often form.
The skin injuries are:

  • red
  • sublime.

They can occur anywhere on the body.
Usually they appear:

  • on the legs,
  • on the upper body.

In some people, the wounds or injuries do not become visible until the skin is scratched or pricked.
The pustules are reminiscent of acne and can occur anywhere on the body.
This eczema is sometimes referred to as “folliculitis.”

Unlike erythema nodosum, which is caused by other diseases (which heal without scarring), the lesions of Behçet’s disease often become ulcerous.

Erythema nodosum
Red and painful nodules that usually appear on the legs and ankles. Sometimes they also appear on the face, neck or limbs.


Primary syphilis is a sexually transmitted disease that causes a papule (syphiloma) on the genitals:

  • Vulva
  • Vagina
  • Cervix
  • Glax and foreskin.

Syphiloma continues to develop into a skin ulcer.

Dermatitis herpetiformis This condition is part of a bullous skin condition (such as pemphigus vulgaris
Dermatitis herpetiformis is an itchy and stinging rash with blisters that occurs when the skin reacts to antibodies of glutens circulating in the blood.
Some call it celiac disease of the skin because it occurs together with celiac disease.
Even though dermatitis herpetiformis can form anywhere on the body, the most common areas are:

  • Elbow
  • Knee
  • Buttocks
  • Back
  • Neck.

In most cases (but not all), it is one of the skin conditions that causes the most itching.

Symptoms of dermatitis herpetiformis
The symptoms of dermatitis herpetiformis come and go, for example:
1. extremely itchy blisters and blisters;
2. the eruption occurs symmetrically on the body in the same size and shape;
3. on the skin it can show up like eczema.


  • The rash of chickenpox starts on the trunk and spreads over the face and extremities.
  • Chickenpox occurs as red papules of 2-4 mm in size and have an irregular outline (rose petal). As a rule, they are extremely numerous: 200-250.
  • As a result, a bubble develops with a thin, transparent wall on the reddened area.
    This skin lesion is very characteristic of chickenpox.
  • After about 8-12 hours, the contents of the vesicle become cloudy, the bubble bursts and then forms a crust.
    The liquid is highly contagious, but the crusts are not considered contagious.
  • As a rule, the crusts fall off after 7 days, sometimes leaving a scar that resembles a hole.
  • Even though the lesion disappears completely in about 7 days according to this cycle, another distinctive indication for chickenpox is that new papules appear every day over the period of about a week.
  • The children are not sent to school until all the bubbles are encrusted.

About one third of diabetics develop a skin problem in their lifetime.
Some of these skin problems are reserved exclusively for diabetics, others occur because diabetics are predisposed to circulatory disorders and infections.
Skin conditions caused by diabetes include:

  • Infections (boils, hailstones, folliculitis and nail bed infections)
  • fungal infections (athlete’s foot and ringworm, which are often localized between the toes)
  • Necrobiosis lipoidica
  • Eruptive xanthomatosis
  • Granuloma annulare disseminatum
  • Vascular lesions in the lower extremities (for example, diabetic foot)
  • Acanthosis nigricans

Cutan lupus erythematosus lupus
is a skin disease with different forms:

  • chronic (discoid lupus erythematosus),
  • subacute
  • acute.

Sun aggravates the problems of cutaneous lupus.
Each type of lupus causes different skin problems, which are listed below:

  1. annular lesions (circular spots with healthy skin in the center) on the face and head;
  2. discus-shaped scaly areas;
  3. Hair loss;
  4. flat rash on the face and body, resembling sunburn;
  5. cutaneous calcification;
  6. small black and purple spots on hands and feet;
  7. sores in the oral cavity and nose;
  8. small red spots on the legs;
  9. Raynaud’s phenomenon;
  10. Palmarerythem.

Bites and stings: insects
fleas and mites often bite humans, but they are not poisonous. Sometimes it is difficult to judge which insect caused the bite or whether the rash is due to a poison sumac or other skin disease.
The following are the most common symptoms:
1. Small relief-like lesions of the skin 2. Pain and itching
3. Dermatitis (inflammation of the skin
4. Allergic reaction in hypersensitive people with swelling or blistering

Impetigo Impetigo
is an infection of the top layer of the skin and is most common in children between 2 and 6 years of age.
As a rule, it develops when bacteria enter a:

  • skin incision,
  • Scratch
  • Insect bite.

Impetigo is caused by the bacterium Staphylococcus aureus, but it can also be caused by streptococci (group A).
The first symptoms are red lesions resembling a pimple and surrounded by reddened skin. On these lesions, a bubble filled with bright liquid is formed.
These injuries can occur anywhere on the body, usually on the face, arms and legs. The lesions fill with pus, then burst after a few days, forming a thick crust.
Itching is common.
If the impetigo is caused by streptococci, the doctor prescribes antibiotics for oral use and an antibiotic-containing ointment for use on the skin.

Skin lesions in children

  • Children can have the same skin problems as adults. Infants and young children have an increased risk of diaper-related disorders.
  • Even though many childhood skin problems disappear in old age, they can still be inherited genetic and permanent skin disorders.
  • Young children have more sensitive skin and are more susceptible than adults to rashes or urticaria as an environmental or food-induced allergic reaction.
    They are also more likely than adults to develop a childhood disease (chickenpox or measles).

In most cases, childhood skin conditions are temporary and can be treated with:

  • Creams
  • warm baths,
  • specific medications.

The most common skin diseases in children include:

  1. Eczema (neurodermatitis)
  2. Diaper rash
  3. Seborrheic dermatitis (cradle cap)
  4. Chickenpox and measles
  5. Warts
  6. Acne
  7. Roseola
  8. Rubella
  9. Urticaria
  10. Ringworm
  11. Rash caused by infections of bacteria or fungi
  12. Rashes after allergic reactions

Precancerous and cancerous skin lesions

Precancerous skin lesions are changes in the skin that can become skin tumors over time.
Precancerous skin lesions include:

  • Keratosis
  • Leukoplakia
  • Xeroderma pigmentosum (moonshine disease)
  • dysplastic nevus.

Precancerous skin lesions: skin tumors

The cancerous lesion can be the result of primary cancer or skin metastasis.
It can look like:

  • a cavity,
  • an open area on the surface of the skin,
  • a nodule,
  • a patch of skin with a map-like pattern.

A malignant lesing can be represented by:

  • bad smell,
  • exudation,
  • Bleeding
  • Itch
  • Pain.

In the case of breast cancer (breast cancer), skin injuries can form:

  • Papules
  • subcutaneous nodules,
  • Vesicle
  • Ulcers.

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