Some of the most common skin diseases are caused by infections, and others are the result of genetic factors combined with environmental factors . In this article we give you some examples of skin diseases caused by different factors, describing their symptoms, treatments and how to prevent them.
Skin and dermatology
To better understand the characteristics of the skin, we recommend reading previous articles such as Rare skin diseases and their relationship with genetics or Basic care for sensitive skin. In them we explain in detail, among other things, that the skin is the largest organ in the human body, and that it is made up of three layers: the epidermis, the dermis and the hypodermis. The skin performs several functions, among which we can highlight its role as a protective barrier that defends our body from the attacks of external agents such as viruses and bacteria, among others.
This protective capacity can be altered if an element inflames or irritates the skin. The discipline that is responsible for studying, preventing and treating the various pathologies that affect the skin as well as healthy skin care is called dermatology. These pathologies that affect the skin can range from primary skin diseases to systemic diseases whose symptoms manifest through the skin. Most skin diseases are not serious, however, they usually cause annoying symptoms that can also influence the patient’s mood, since most of them are usually visible.
7 common skin diseases and their origin
The origin of skin diseases can be very diverse. As we have mentioned before, some are the result of fungal or viral infections, while others are caused by environmental and genetic factors or may even be caused by immunological problems.
Next, we are going to look at some of the most common skin diseases, including one whose cases have increased worryingly in recent years: melanoma, which is a type of skin cancer.
Vitiligo
Vitiligo is characterized by the appearance of white spots of different sizes on different parts of the body , mainly those most exposed to the sun, such as the hands, arms, face, and feet. The spots have well defined edges and sometimes these have a darker or reddish appearance. In addition, vitiligo usually leads to the early appearance of gray hair, especially in the areas of the spots.
The disease occurs as a result of the destruction or malfunction of melanocytes, which are the cells that produce melanin (pigment that determines the color of hair and skin). Therefore, although it affects all skin types, it is more noticeable in dark-toned skin.
It is not a contagious disease nor does it have a serious prognosis , however, it can cause sunburn or skin cancer, among other complications. The skin affected by vitiligo rarely recovers its color , and most of the time, the lack of pigmentation extends to various parts of the body.
Once vitiligo has been diagnosed, through blood tests or biopsy, treatments can be started to balance skin tone, such as:
- Depigmentation of unaffected areas.
- Medications with corticosteroid creams.
- Activation of melanocytes by exposure to UVA rays.
- Surgery.
The cause of the disease is still unknown, although many investigations indicate that the culprit may be the combination of genetic and environmental components.
Specifically, research indicates that vitiligo has a polygenic inheritance pattern, that is, there are multiple alleles that contribute to the genetic risk of the disease.
The relationship between genetics and the development of vitiligo has long been suspected, since first-degree relatives of people with this disease have a higher incidence of vitiligo than the general population. Specifically, the siblings of affected people have a prevalence of 6% that increases to 23% in the case of twins.
Regarding environmental factors, it has been observed that exposure to various chemical substances, such as phenolic compounds, alter the synthesis of melanin and, therefore, can trigger vitiligo.
Acne
Among skin diseases, acne is the most common and best known. It has a prevalence of 80% in people between the ages of 11 and 30, although its peak incidence is reached in women between the ages of 14 and 17 and in men between the ages of 16 and 19.
In general, acne, in any of its degrees, usually remits spontaneously between the ages of 20-25, although some women suffer from it beyond the age of 40.
The disease is characterized by the appearance, usually on the face, of comedones (pimples with sebum) that can break and become infected, turning into pustules or even forming cysts.
Acne occurs because hair follicles become clogged with dead skin cells, bacteria, or dried sebum that builds up and blocks sebum that should be coming to the skin’s surface through the pores.
Depending on the damage to the skin and the number of pimples present, acne can be mild, moderate, or severe.
It is a multifactorial disease, that is, it is caused by the intervention of several factors, which in this case are genetic, environmental and individual skin factors.
Several studies have recently shown the heritability of acne. Recent research from the King’s College Institute of Dermatology and King’s College geneticists found 15 acne-related genetic variants that influence the shape of hair follicles, making them more prone to bacterial inflammation.
The trigger for acne is usually puberty, a stage in which a hormonal change occurs, especially an increase in androgens, and this causes the stimulation of the sebaceous glands.
Although it usually disappears spontaneously, a dermatologist can recommend in each case treatments focused on relieving the signs of acne.
Skin cancer
This type of cancer arises when abnormal skin cells grow out of control, due to damage to their DNA caused mainly by ultraviolet radiation.
Although it is more frequent in areas of the body exposed to the sun such as the face, neck, chest, arms and legs, it can also occur in areas that are not normally exposed, such as the palms of the hands or under the nails.
Among the types of skin cancer that exist, melanoma is the most dangerous, since in its advanced phase it can spread to internal organs and therefore put the person’s life at risk.
Detected in time, it is usually curable, which is why we must pay close attention to its first manifestations, which include:
- Large brown spots with smaller dark specks.
- Moles that change size, color, or have bleeding.
- Small lesions with an irregular border and reddish, white or bluish parts.
- Lesions accompanied by itching or burning.
- Dark lesions on the palms of the hands, soles of the feet, or on the mucous membranes of the mouth, nose, vagina, or anus.
The number of melanoma cases has tripled in the last 20 years . The proliferation of outdoor activities or tanning salons are some of the reasons being considered to explain this large increase.
The main treatment for this type of skin cancer is surgery to remove the malignant growth. If the cancer is advanced, treatment with chemotherapy, radiotherapy or immunotherapy is carried out to slow down the progression of the disease.
Environmental and genetic factors are involved in the development of this disease . In approximately 10% of cases, melanoma occurs in several members of the same family. These familial cases are normally due to hereditary genetic changes that increase the risk of developing this type of cancer. Today several genes associated with melanoma are known, although the most studied are CDKN2A and MC1R.
Regarding environmental factors, intense exposure to the sun stands out. For this reason we must be aware of the importance of using protection, especially on the face, every month of the year , as we explained in the post The importance of using facial sunscreen all year round.
Athlete’s foot
This skin disease is an infection caused by a fungus, and it usually starts between the toes. The disease is characterized by rashes that may be accompanied by itching and burning and may cause scaling.
The foot of fin is very contagious, since it can spread easily to other parts of the body of the affected person or to other people by having contact with the infected part or sharing, for example, a towel.
The fungus that causes fin foot is the same fungus that causes ringworm. It is a microorganism whose growth is favored in humid and warm environments . That is why some practices that increase the risk of contracting this skin disease are:
- Regularly wear wet or very tight socks and shoes.
- Sharing shoes, bedding, or mats with someone who has the infection.
- Walking barefoot in public places favorable to the development of the fungus, such as saunas, changing rooms, swimming pools or common showers.
Fin foot is treated with antifungal creams, which destroy the fungus.
Warts
Warts are benign epidermal growths that can appear anywhere on the body , although they are more common on fingers and hands.
They are usually asymptomatic, although they can sometimes cause mild pain, and although they usually disappear on their own after a couple of years, they can also be eliminated earlier through treatments such as the application of drugs with salicylic acid or cryotherapy, which consists of in applying liquid nitrogen to the wart, among others.
Warts are caused by some types of human papillomavirus, of which there are at least 150 variants.
Viruses that cause warts can be spread by skin contact or by sharing objects.
Because it is an infection, each person’s immune system responds differently, and young children or those weakened by diseases such as AIDS or transplants are more vulnerable.
Psoriasis
Psoriasis is caused by an acceleration of the life cycle of skin cells, which causes them to accumulate on the surface of the skin, giving rise to scales and reddish spots that cause itching and even pain.
Symptoms vary from person to person, but the most common are:
- Red spots on the skin covered with scales.
- Dry, cracked skin that may even bleed.
- Itching, burning and pain.
- Thicker than normal and cracked nails.
- Swollen joints.
Psoriasis manifests itself in flare-ups, which can last for weeks or months and then subside, although they reappear after a while as it is a chronic disease with no cure. For this reason, symptom control is the main objective of the treatments , which can be of three types:
- Topical: creams, usually with corticosteroids that are applied in mild cases of psoriasis.
- Phototherapy: it is based on radiation with ultraviolet light, either natural or artificial.
- Systemic medications, such as retinoids: they are used in more pronounced cases of psoriasis or when it is resistant to other treatments.
Psoriasis is multifactorial, since both genetic and environmental factors are involved.
Having parents with psoriasis has been shown to increase the risk of contracting this very disease. In a meta-analysis comparing genetic variations in 39,000 participants, 16 markers associated with psoriasis were identified.
Among the environmental factors that increase the chances of suffering from psoriasis, we find a weakened immune system, high levels of stress, obesity or smoking.
