Warts and verrucas
Warts are benign lesions that occur in the mucosa and skin , caused by infection of keratinocytes with human papilloma virus ( HPV )
group of nonenveloped DNA viruses of genus Papillomavirus diverse group of viruses which infect mainly the epithelial and mucosal tissues more than 200 distinct types based on similarities within their DNA sequences most can infect the cutaneous epithelium and cause skin warts specific types of infecting HPV are correlated with histological characteristics and to a lesser extent with morphological features of warts infection with HPV is the most common STI affecting about 80 % of the population two broad categories of HPV (1) low risk HPVs which cause anogenital and cutaneous warts (2) high risk HPVs causing oropharyngeal ( oral ,tonsil and throat areas ) and anogenital cancers oncogenic HPVs cause almost all of cervical cancers , 90 % of anal , 70 % of vaginal , 40 % of vulvular , 50 % of penile and 13 % to 72 % of oropharyngeal cancers
Spread- spread via direct skin to skin contact or via the environment direct skin or mucous membrane contact with friction indirect contact with contaminated surfaces as gymnasium floors or around swimming pools, fomites , socks , shoes , towels and sports equipment HPV does not infect other species- humans are the only reservoir incubation period can vary from few weeks to more than an year warts are common in childhood but can happen in any age.
What happens – infect and disturb the cutaneous & mucosal epithelial cells of the anogenital tract , hands or feet causing a variety of diseases events which disrupt the integrity of normal epithelial barrier ( e.g abrasions or other microtrauma ) increase the likelihood of infection , HPV does not cause systemic viremia most infections resolve spontaneously but a small proportion become persistently infected HPV is pervasive ,it involves physical evasion from the immune cells recognition through HPV restoration and protection within infected cell nuclei HPV also down regulates the major histocompatibility complex class I ( MHC I ) HPV virus can survive for many months to years at low temperatures without a host epidermal thickening and hyperkeratinization occurs at basal layer and clonal proliferation which eventually leads to a visible wart weeks or even months later warts may persist for years in adults whereas in children spontaneous resolution can happen within a few months.
Who is at risk – it is estimated that about 40 % of the population if infected with HPV and warts develop in about 7 % to 12 % increased exposure to HPV increased risk of epidermal barrier penetration inappropriate immune response / immunosuppressed / organ transplant age -happen more commonly in children and adolescents and rare in age group < 5 certain occupations as – regular handling or meat or fish ( butchers shop or slaughterhouse workers ) also called Butchers warts children ( other classmates with warts ) and teenagers ( sharing towels etc ) if other family members are affected by warts people with atopic disease as eczema
Common warts verucca vulgaris – seen often on back of hands , knees , toes and around nails can be single or multiple of varying sizes associated with HPV types 2 , 4 followed by types 1, 3 , 27 , 29 and 57 skin-coloured , flat or firm dome shaped papules rough , papillomatous and hyperkeratotic surface with sharp borders
Plantar warts ( Verruca plantaris ) cutaneous lesions on the plantar aspect of the foot plantar warts exhibit an annual incidence of 14 % in the general population they may present as singular rough , flesh colored to yellow grey-brown , hyperkeratotic papule or a thickened ‘ cobblestone ‘ plaque called a mosaic wart which is multiple plantar warts that have coalesced ( mosaic ) normal skin lines ( dermatoglyphics ) are disrupted by plantar warts also noticed are small black dots which are formed by thrombosed capillaries within the lesion and they exhibit pinpoint bleeding when the wart is pared the above features ie thrombosed capillaries ( seen as black dots ) , pin point bleeding and disruption of the normal skin lines help in differentiation of plantar wart from other lesions as calluses or corns.
Flat warts ( verruca plana ) multiple small flat topped skin colored papules can have slight elevation and 2-4 mm in diametre mostly on the face , hands and shins – mostly skin coloured but can be some times lighter or darker than the surrounding skin commonly seen during childhood or early adulthood mostly caused by HPV types 3 , 10 , 28 and 41
Filiform wart – cluster of fine fronds emerging from a narrow pedicle base -found usually around the face frond like projections that exhibit quick proliferation
Periungual warts- around fingernails and toenails – often painful can be seen more commonly in people who bite their nails thickened cauliflower like lesions periungual warts can subsequently lead to onychodystrophy from nail matrix damage.
Genital warts -one of the most common form of STI affecting the general population external genital warts ( EGW ) -also known as condylomata acuminata types 6,11 cause genital warts and transmission is usually via penetrative sex , about 90 % of of those who are exposed and contract HPV will not develop genital warts incubation period ranges from 3 weeks to 8 months after initial contact highly infectious and -abouy 65 % of individual with an infected partner develop EGW within 3 weeks and 8 months can be in anal or genital area – penile shaft , scrotum , vagina or labia majora can also be found in internal surfaces of the vagina and the anus EGWs can occur separately or in clusters -in size they can be small ( 5 mm or less ) or spread and become large masses they can be skin coloured or darker and may bleed.
Differentials – calluses and callosities corns molluscum lichen nitidus ( inflammatory skin condition in children ) actinic keratoses ( hypertrophic ) syringoma ( benign sweat duct tumours ) lichen planus knuckle pads squamous cell carcinoma melanocytic lesions focal palmoplantar keratoderma.
Presentation -mostly asymptomatic some may cause itching , tightness or a feeling of pressure warts can be painful if they are at sites that are exposed to pressure such as the soles of feet
Observe – location how many size , colour , shape associated changes as ○ lichenification ○ scratch marks ○ ulceration ○ erosion ○ fissure ○ granuloma ○ hypertrophy palpate ( wear gloves ) ○ plantar warts can feel rough and can be tender when squeezed along sided warts can appear in groups of close-together lesions called mosaic warts carry out a general examination if you suspect an underlying condition as immunosuppression.
Diagnosis – diagnosed mainly clinical examination and physical findings in most cases further investigations for diagnosis is not required paring down with a file will cause pinpoint bleeding from thrombosed capillaries genital warts can also be normally recognised by visual inspection – if the diagnosis is in doubt refer for possible biopsy it should also be kept in mind if you are dealing with external genital warts that patients with one type of STD often are also infected with other STD’s.
Complications – autoinoculation ( spread of viral particles ) localised infection pain ( for e.g due to plantar warts ) can cause functional limitations if the immune function is impaired the warts can be large , extensive and resistant to treatment some times people with immunodeficient conditions as lymphoma , idiopathic CD4 lymphocytopenia or HIV infection may present with warts as the initial presenting feature can infect others psychosocial impact ( teasing , embarrassment , swimming permission refusal ) nail dystrophy and destruction ( periungual warts ) cancerous transformation of warts ( rare but lesions may transform into SCCs -epidermodysplasia verruciformis )
British Association of Dermatology leaflet on plantar warts https://www.bad.org.uk/library-media/documents/Plantar%20Warts%20Update%20Apr%202012%20-%20lay%20reviewed%20Apr%202012(2).pdf
American College of Foot and ankle surgeons on plantar warts https://www.acfas.org/footankleinfo/Plantar_Wart.htm
A printable leaflet from Sheffield Teaching Hospitals https://www.sth.nhs.uk/clientfiles/File/VP_pub%20new%20nov%202011.pdf
Warts in children and teenagers https://raisingchildren.net.au/guides/a-z-health-reference/warts
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- Warts and verrucas : assessment and treatment The Pharmaceutical Journal https://pharmaceutical-journal.com/article/ld/warts-and-verrucas-assessment-and-treatment