The skin is the largest organ in the human body and plays a crucial role in protecting our body from external factors. However, the skin can also be susceptible to a variety of diseases and conditions that can affect its appearance and function. In this article, we will explore the 24 most common skin pathologies, their distinctive characteristics and how to recognize them to seek the appropriate treatment.

1. Acne

Features:

Acne is a common skin condition that develops when hair follicles become blocked with oil and dead skin cells. It can manifest as pimples, whiteheads, blackheads and cysts. The severity of acne varies from mild cases to more severe forms that can leave scars.

How to recognize it:

Acne usually appears on the face, neck, back and shoulders. The pimples may be red and inflamed, with pus inside. Additionally, there may be pain and tenderness in the affected areas.

2. Psoriasis

Characteristics:

Psoriasis is an autoimmune disease that causes the accumulation of skin cells on the surface of the skin, forming red, scaly plaques. It can cause itching, pain and peeling in the affected areas.

How to recognize it:

Psoriasis plaques usually appear on the elbows, knees, scalp and lower back. They have a silvery, scaly appearance and can be easily irritated.

3. Atopic dermatitis

Characteristics:

Atopic dermatitis is a chronic skin disease that manifests itself with redness, itching and dryness. It usually affects people with a family history of allergies or asthma.

How to recognize it:

The skin of people with atopic dermatitis may be very dry, irritated and swollen. Eczema often occurs in folds of the skin, such as elbows and knees.

4. Hyperpigmentation

Features:

Hyperpigmentation refers to the appearance of dark spots on the skin due to the overproduction of melanin. It can be caused by sun exposure, hormonal changes, or inflammation.

How to recognize it:

Areas of hyperpigmentation can vary in size and shade, from small spots to larger patches. They are usually dark brown or black and may appear in areas exposed to the sun.

5. Hives

Characteristics:

Hives are an allergic reaction that manifests itself with reddish, raised welts on the skin, accompanied by intense itching. It can be triggered by food, medications or insect bites.

How to recognize it:

Hives are temporary and usually disappear within a few hours. They can change shape and size quickly, and often appear in groups.

6. Rosacea

Characteristics:

Rosacea is a chronic condition that manifests itself with facial redness, small visible blood vessels, pimples and burning skin. It can worsen with triggering factors such as the sun, stress or certain foods.

How to recognize it:

Facial redness, especially in the cheeks, nose, forehead and chin, is one of the main signs of rosacea. Papules and pustules may also appear on the skin.

7. Seborrheic dermatitis

Features:

Seborrheic dermatitis is a chronic skin condition that causes peeling and redness in oily areas such as the scalp, face and chest. It is believed to be related to an excessive growth of a fungus called Malassezia.

How to recognize it:

Seborrheic dermatitis manifests itself with greasy scales on the scalp, eyebrows, eyelids and ears. . It may cause itching and a burning sensation in the affected areas.

8. Keratosis pilaris

Features:

Keratosis pilaris is a common skin condition characterized by the appearance of small, rough bumps on the skin, especially on the arms, thighs, buttocks and cheeks. These bumps are usually harmless but can be unsightly.

How to recognize it:

Keratosis pilaris bumps are generally skin-colored or slightly reddish. They may worsen in winter or with dry skin.

9. Vitiligo

Characteristics:

Vitiligo is an autoimmune disease that causes loss of pigmentation in the skin, resulting in white or depigmented spots. It affects people of all ages and races, and its exact cause is unclear.

How to recognize it:

Vitiligo spots are symmetrical and usually appear in areas exposed to the sun, such as hands, face, arms and feet. They can vary in size and shape, and do not produce symptoms beyond aesthetic appearance.

10. Epidermal cysts

Characteristics:

Epidermal cysts are benign lumps that form under the skin and contain keratin and other debris. They are usually soft to the touch and do not cause pain unless they become infected.

How to recognize them:

Epidermal cysts are round, firm bumps that can move under the skin. They are often yellowish-white and can grow slowly over time.

11. Melasma

Characteristics:

Melasma is a skin condition characterized by the appearance of dark, symmetrical spots on the skin, especially on the face. It is believed to be related to hormonal changes, sun exposure and genetic predisposition.

How to recognize it:

Melasma spots are usually dark brown or grayish in color and may appear on the forehead. , cheeks, upper lip and chin. They tend to worsen with sun exposure.

12. Molluscum contagiosum

Characteristics:

Moluscum contagiosum is a viral skin infection that manifests itself with small pearly bumps on the skin. It is common in children but can affect people of all ages.

How to recognize it:

The bumps of molluscum contagiosum are soft to the touch and are usually white or pearly in color. They can appear anywhere on the body, especially in humid areas.

13. Lichen planus

Characteristics:

Lichen planus is an inflammatory skin disease that manifests itself with flat, reddish, line-shaped lesions on the skin. It can cause intense itching and discomfort in the affected areas.

How to recognize it:

Lichen planus lesions are flat, shiny and can form lines on the skin that look like webs. They usually appear on the arms, legs, oral mucosa and genital area.

14. Molluscum dermatitis

Features:

Moluscum dermatitis is a common skin condition in children caused by inflammation of the skin around molluscum contagiosum. It can cause redness, swelling and itching in the affected area.

How to recognize it:

The skin around molluscum contagiosum may appear red, blistered or papuled. The affected area may be sensitive to the touch and cause discomfort.

15. Tinea versicolor

Features:

Tinea versicolor is a fungal skin infection that causes scaly, discolored spots to appear on the skin. It is usually more common in warm and humid climates.

How to recognize it:

Tinea versicolor spots can be white, light brown or pink and usually appear on the trunk, neck, arms and legs. They may worsen with sun exposure.

16. Impetigo

Characteristics:

Impetigo is a bacterial skin infection that manifests itself with pus-filled blisters that break and form scabs. It is contagious and can affect people of all ages, especially children.

How to recognize it:

Impetigo blisters are usually small, red and filled with yellowish fluid. When broken, they form golden scabs that can be painful and itchy.

17. Nummular eczema

Characteristics:

Numular eczema, also known as nummular dermatitis, is a form of eczema that manifests itself with circular, scaly lesions on the skin. It can be chronic and recur frequently in some people.

How to recognize it:

Numular eczema lesions are round, red, with well-defined edges and a scaly appearance. They can cause intense itching and skin discomfort.

18. Actinic keratosis

Characteristics:

Actinic keratosis is a precancerous skin lesion caused by chronic exposure to the sun. It manifests itself as rough, scaly patches on areas exposed to the sun, such as the face, neck and back of the hands.

How to recognize it:

Actinic keratoses are generally rough to the touch and red, brown or skin color. They can grow slowly and increase in number over time.

19. Seborrheic keratosis

Characteristics:

Seborrheic keratosis is a benign skin condition that manifests itself with brown, black or yellowish spots on the skin. They are usually raised and have a waxy appearance.

How to recognize it:

Seborrheic keratoses usually appear on the scalp, face, neck and trunk. They do not usually cause symptoms, except in cases of irritation or aesthetic discomfort.

20. Shingles

Features:

Herpes zoster, also known as shingles, is a viral infection that causes painful skin rashes, blisters, and a tingling sensation. It is caused by the varicella zoster virus, which remains dormant in the body after chickenpox.

How to recognize it:

Shingles rashes usually appear on one side of the body in the form band or stripe. The blisters may break and form scabs, and the pain may be intense in the affected area.

21. Cellulite

Characteristics:

Cellulitis is an infection of the skin and soft tissues that causes redness, swelling, heat and sensitivity in the affected area. It can be caused by bacteria such as streptococcus and staphylococcus.

How to recognize it:

The skin affected by cellulite is usually red, hot to the touch and painful. Swollen, tender areas may appear, and the infection can spread quickly if not treated properly.

22. Granuloma annulare

Characteristics:

Granuloma annulare is a benign skin rash that manifests itself as ring-shaped bumps on the skin. It most commonly affects children and young adults and its exact cause is unclear.

How to recognize it:

Granuloma annulare lesions are round or oval, with a raised edge and centrally depressed . They can vary in size and color, and often do not produce symptoms beyond aesthetic appearance.

23. Pityriasis rosea

Features:

Pityriasis rosea is a common skin condition that manifests itself with pink, scaly, oval spots on the skin. It often begins with an initial lesion called a "herald patch".

How to recognize it:

Pityriasis rosea lesions usually appear on the trunk, arms and legs, and form patterns on Christmas tree shape. They may cause mild itching and peeling in some people.

24. Angioedema

Characteristics:

Angioedema is a subcutaneous swelling that affects the skin, mucous membranes and submucosal tissues. It can be caused by an allergic reaction or genetic factors, and can cause itching and discomfort in the affected area.

How to recognize it:

Angioedema manifests itself with sudden and often asymmetrical swelling on lips, eyelids, cheeks, tongue or throat. It may be accompanied by redness and a sensation of heat in the inflamed area.