THE ROLE OF DERMOSCOPY IN THE DIFFERENTIAL DIAGNOSIS OF SKIN DISEASES CAUSED BY HUMAN PAPILLOMA VIRUS

Human papillomavirus (HPV) is a highly contagious viral infection that is spread between people through direct contact or contaminated objects. According to Centers for Disease Control and Prevention, HPV is the most common sexually transmitted infection. There are over 350 genotypically different types of HPV; most of them cause different types of warts. Many of known genotypes are harmless or are considered "low-risk" types, but 12 geno-types have a high carcinogenic effect. This situation is oneof the main reasons for improving the prevention, early diag-nostic and timely treatment of papilloma virus infection of different localizations. Doctors of different specialties have a common goal to unite in order to prevent this disease. The term "wart"includes all morphological types of warts and is sometimes used to describe wart-like growths, such as seborrheic keratomas, epidermal and intradermal nevi, sebaceous gland hyperplasia, and other benign and sometimes malignant tumors. Dermoscopy can provide additional information on the structural elements of small wart-like growths. Due to the clinical variability of warts and similar skin growths, they can be represented by different dermoscopic features. Common warts on dermoscopy usually appear in the form of grouped papillae with dotted or loop-like vessels, hemorrhagic points, and lines in various combinations, often centrally located and surrounded by a whitish halo. Plantar warts on dermoscopy are represented by small punctate hemorrhagic structurescorresponding to thrombosed vessels and are visualized inside whitish or yellowish papillae, which destroy the skin pattern. Flat warts do not contain specific dermoscopic signs or may be represented by single dotted vascular or hemorrhagic inclusions. Filamentous warts have the same features as normal warts, but due to the elongated papillae, long loop-like vessels they are usually better visualized. The most common dermoscopic finding of genital warts is the so-called mosaic pattern, namely the presence of grouped centrally located dotted or glomerular vessels surrounded by a whitish reticular line, as well as a finger-shaped pattern associated with looped vessels. Sometimes, papilloma can be pigmented by mimicking the clinical aspect of seborrheic keratosis, but keratosis is characterized by a pattern of centrally located vessels, which looks like "frog caviar" (frogspawn-like) but formed by other types of vessels. Differential diag-nosis of intradermal nevi is usually not difficult. However, when the elements have a pronounced papillomatous pattern, it may be necessary to assess the structural features of the growth. Most often, the vascular pattern is represented by curved vessels in the middle of clots of body or weakly pigmented colour. Dermatoscopic signs of keratoacanthoma are the detection of a centrally located crater filled with yellow keratin masses and surrounded by a whitish border. It can be relatively homogeneous and little transparent, or polymorphic vessels can be found in it. Dermoscopy may also be helpful in the differential diagnosis of molluscum contagiosum. In contrast to warts, there is a domed protrusion with umbilical indentation, which is filled with white, yellow, or combined amorphous structures. The peripheral zone is more often represented by so-called corona-like vessels.Knowledge of these features can be useful for choosing the right treatment.