Acne vulgaris is a common chronic skin disease involving blockage and/or inflammation of pilosebaceous units (hair follicles and their accompanying sebaceous gland). Although 85% of cases appear among adolescents, often the disease affects the adults. Acne can present as noninflammatory lesions, inflammatory lesions, or a mixture of both, affecting mostly the face but also the back and chest.

Acne vulgaris is characterized by noninflammatory, open or closed “comedones” and by inflammatory papules, pustules, and nodules.

Acne vulgaris typically affects the areas of skin with the densest population of sebaceous follicles (e.g. face, upper chest, back). Local symptoms of acne vulgaris may include pain, tenderness, or erythema. Systemic symptoms are most often absent in acne vulgaris.

Apart from scars, Acne affects mostly psychology and cause low self-esteem. In accordance with research, it causes depression and, in some cases, might be cause for suicide. As it appears during adolescence when young people feel insecure, the rapid and intense treatment is recommended in order to reduce negative consequences.

Urticaria is a disease characterized by the development of wheals (hives), angioedema, or both. Urticaria needs to be differentiated from other medical conditions where wheals, angioedema, or both can occur as a symptom, for example skin prick test, anaphylaxis, auto-inflammatory syndromes, or hereditary angioedema (bradykinin-mediated angioedema).

A wheal consists of three typical features:
1. It is characterized by a central swelling of variable size, almost invariably surrounded by a reflex erythema.
2. It is associated with itching or sometimes a burning sensation.
3. It has a fleeting nature, with the skin returning to its normal appearance, usually within 1 - 24 h. Sometimes wheals resolve even more quickly.

Urticaria is distinguished into acute urticaria, when it lasts less than 6 weeks and in chronic urticaria, when there is daily or almost daily appearance of new wheals, for a period of more than 6 weeks.

Fungal infections of the skin and its components include fungal infections of the skin, hair and nails which are caused by microorganisms called fungi. Depending on the fungus that has caused the infection, skin fungal infections are divided into dermatophytes, candidiasis, dandruff, and unusual fungal infections caused by rare fungal species. Dermatophytes are caused by microorganisms called dermatophytes and selectively invade the keratinized tissues of humans and animals.

Fungal growth is enhanced by the influence of certain factors, such as taking certain antibiotics, diabetes, frequent intravaginal lavage, IUD (IntraUterine Device), pregnancy, poor hygiene and taking cortisone. Some forms of fungal infections are transmitted through skin contact, using contaminated objects such as combs, towels, seat backs, and through the sea or pool, due to the moisture that promotes the growth of fungi.

Common Warts are painful benign lesions of the skin, known for thousands of years.

They are caused by the human papillomavirus (HPV). The disease is contagious. Transmission of the disease occurs mainly through direct contact or indirectly through shared objects and then use public spaces, eg public baths and swimming pools. The Common warts usually appear when there is a large slit in the skin when a person is infected with the virus HPV or areas where the skin is exposed to excessive moisture such as sweaty feet. Experiments have shown that the incubation time of ants ranges from 1 to 20 months, with an average of 4 months.

Depending on the clinical picture and the location, the common warts are divided into common, smooth, and plantar warts.

Psoriasis is an immune-mediated chronic and multifactorial inflammatory disorder that involves hyperproliferation of the keratinocytes in the epidermis which manifests as dermatologic lesions. This common dermatological disorder is associated with a variety of other diseases commonly referred to as comorbidities.

Patients with psoriasis are more likely to develop cardiovascular disorders, diabetes, metabolic syndrome and depression. Moreover, patients suffering from psoriasis have reduced quality of life (QoL) and they are exposed to social stigma and discrimination.

Psoriasis affects more than 125 million people worldwide. The estimated global prevalence is of 2–3%, and there is evidence to suggest that may be increasing. Up to one-third of patients with psoriasis has a moderate-to-severe form of the disease.

The occurrence of psoriasis varies according to geographic region. Caucasians are more affected compared to other ethnic groups. As well, within Europe, North-Eastern and Southern countries showed higher estimates in prevalence. These variations occurs probably due to genetic and environmental factors.

Psoriasis is considered equally prevalent in both sexes and can occur at any age, although it is less common in children than in adults. The onset of psoriasis occurs most commonly at around 16–22 years of age and again at around 57–60 years of age.

The cause of psoriasis is not fully understood, but a number of risk factors are recognised. These include family history and environmental risk factors, such as smoking, stress, obesity, and alcohol consumption, which determine the degree of severity.

The most common parts of the body where the disease appears are the knees, elbows, scalp and nails.

Psoriasis has a complex architecture and can manifest as various phenotypes. Multiple phenotypes might occur in the same individual.

Τhe most common type of psoriasis is Plaque psoriasis (also known as psoriasis vulgaris), affecting about 90% of people with psoriasis.

Other types of psoriasis are Guttate or eruptive psoriasis, Inverse psoriasis, Pustular psoriasis and the Erythrodermic psoriasis.

Early treatment may be important in addressing the development of comorbidities such as cardiovascular disease and psychosocial issues.