Skin Bacterial Infections
Impetigo contagiosa
Impetigo is a skin infection caused by staphylococcus or streptococcus, leading to the formation of small blisters filled with pus or fluid, which, after bursting, leave golden-yellow crusts. It can appear on any part of the body, but is most commonly seen around the mouth and nose, as well as around the buttocks and hands. It is more frequent in children during the summer months, particularly in those with already damaged or irritated skin. The infection is often transmitted by scratching from one part of the body to another and can also spread to others through touch or scratching. Treatment involves antibiotic creams, and in more extensive forms of the disease, oral antibiotics are required.
Erysipelas or Red Wind
Erysipelas is an acute infectious disease (cutaneous cellulitis and lymphangitis) caused by the β-hemolytic streptococcus group A. The infection most commonly appears on the face, arm, or leg, with the entry point typically being injured skin. Lymph nodes around the infected area may become enlarged and painful, and people with particularly severe infections may develop fever and chills. In most patients, there is a rapid increase in body temperature, up to 39–40°C. At the same time, symptoms such as general weakness, headache, nausea, and vomiting occur. The affected area becomes intensely red, and the skin is warm, tight, shiny, painful, and sharply demarcated from the surrounding skin. Mild infections are usually treated with oral penicillin or erythromycin for 2 weeks, while more severe infections require antibiotic injections. Penicillin is the most effective antibiotic in the treatment of erysipelas and should be administered as soon as possible to prevent more severe infections and spread to other organs.
Fungal Skin Infections (Dermatomycoses)
The most common causes of dermatomycoses are: dermatophytes, yeasts, and less commonly molds.
Dermatophytoses are dermatomycoses caused by dermatophytes, which include fungi of the genera Microsporum, Trichophyton, and Epidermophyton. A common characteristic of these fungi is the degradation of keratin by a specific enzyme, and the clinical presentation varies depending on the pathogenicity of individual dermatophyte strains and the location of the lesions.
Among dermatomycoses caused by yeasts, the most common infection is caused by Candida (most often Candida albicans), which can cause not only skin and mucosal infections but also systemic infections, which are much more dangerous.
The diagnosis is made based on medical history and clinical presentation, and mycological examination of the lesion, which consists of a native microscopic preparation and fungal culture. In some cases, examination with a fluorescent lamp (Wood’s lamp) is necessary.
Therapy depends primarily on the location of the lesions (skin, scalp, or nails), the degree of skin damage, the depth of pathogen penetration, and the type of fungus causing the infection. Typically, topical antifungal creams are sufficient, but for widespread skin infections, scalp mycoses, and onychomycosis (nail infections), systemic treatment is necessary.
Viral Skin Infections
Diseases Caused by Herpes Simplex Viruses
Herpes Simplex Virus (HSV) types 1 and 2 cause infections of the lips, face, and genital area. The infection manifests as redness of the skin covered with tightly clustered small blisters. A possible complication is a secondary bacterial infection. Treatment is symptomatic with local therapy; topical acyclovir, foscarnet, and zinc paste. In moderately severe genital HSV infections, oral acyclovir, valacyclovir, or famciclovir may also be taken.
Herpes Zoster
The cause of the disease is the Varicella Zoster virus. Primary infection with this virus causes chickenpox, which typically occurs in childhood. Herpes zoster occurs when the latent virus is activated in people who have had chickenpox, and therefore it is much more common in adults. Up to three weeks before skin lesions appear, pain and a burning sensation occur in the area of the skin along the nerve that the affected nerve innervates. Redness appears on the affected skin, followed by tightly clustered blisters filled with pus or blood. The most important treatment consists of analgesics to prevent pain, oral acyclovir, vitamin B, and, if necessary, topical antibiotic ointment, as well as powder with anesthesin as a magistral preparation.
Molluscum Contagiosum
The causative agent is a DNA poxvirus called Molluscum contagiosum virus (MCV) that infects only humans. The virus spreads from person to person through contact with damaged skin and can be transmitted through towels, clothing, or toys. In infected individuals, the virus spreads easily through contact or scratching to other areas of the body. It most often presents as dome-shaped, glossy papules, 1 to 5 mm in diameter. The infection is localized to the upper layer of the epidermis and heals without scarring unless scratching causes deeper layers to be damaged, leading to bacterial infections. Most lesions disappear within two years (usually within 9 months). As long as the skin lesions are present, the infection can spread to other parts of the body or other people. Once the lesions are gone, the possibility of spreading the infection ceases. Unlike herpes viruses, which remain inactive after skin or mucosal lesions have healed, Molluscum contagiosum virus completely disappears along with the papules, unless the person is reinfected.
Diseases Caused by Human Papillomavirus (HPV)
Human Papillomaviruses (HPV) with numerous types (more than 150) cause various types of mostly benign viral papillomas on the skin and mucous membranes.
Common warts are a common type of warts that appear as hard, hyperkeratotic papules, up to 1 cm in size, but they may appear larger when multiple warts cluster together. They are brown or skin-colored. They most commonly develop on the hands, fingers, and sometimes near or under the nails.
Plantar warts appear individually or in groups on areas with thick layers of skin. They are painful when walking, are more flattened, and grow deeper, causing pain.
Flat juvenile warts (Verrucae planae juveniles) are barely raised above the skin level, flat, skin-colored, light brown, or grayish. They appear on the face, the backs of the hands, and less frequently on other areas.
Genital warts (Condylomata acuminata) appear in the anogenital area (prepuce, glans penis, labia, anus, vagina, urethra). They are soft, elongated warts, pink in color, on a stalk, with a cauliflower-like surface. These warts are most often transmitted through sexual contact. They can be caused by HPV virus types with low risk (types 6, 11) and high risk (types 16, 18, 31, 33, 35).