Warts are defined as generally round skin growths. We all know this description prevalent in the general population, it is enough to pay attention to a specific area of our body to discover them. What not everyone knows is that these are skin lesions of viral origin.
It’s true, warts close many more secrets than initially thought: they are infections of the skin and / or mucous membranes caused by the family of viruses Papillomaviridae, better known as the human papillomavirus. (HPV).
There are over 100 types of HPV, of which at least 14 are considered oncogenic (high risk). This is not anecdotal fact, as subtypes 16 and 18 are responsible for over 70% of cervical cancer cases. In addition, over 99% of cases of this type of cancer are correlated with genital HPV infection. Who would say that an injury as harmless as a wart and cancer as deadly share a causative agent in the same family?
If you want to know more about types of warts, Its global impact, the process underlying its formation, and many more questions, keep reading.
Types of warts: a world beyond the gra
Warts are some lesions varying in shape and protruding, usually globular in shape. They occur in different areas of the skin, so we will distinguish the type of wart based on its location in the patient’s body. U.S. National Library of Medicine collects classification:
- Common warts: they usually appear on the hands, but also on the rest of the body.
- Flat warts: usually found on the face and forehead. Common in children.
- Genital warts: As the name suggests, they appear in the pubic area, between the thighs and in the genital areas.
- Plantar warts: on the soles of the feet.
- Subungual and periungual warts: they appear under or around the nails.
- Mucosal papillomas: again, as the name suggests, they appear in the oral and vaginal mucous membranes.
At this point, it should be clarified that we are dealing with benign cell proliferation, that is to say non-cancerous. They are a very common cause of doctor visits, as it is estimated that 0.8-22% of the teenage population may have them. Additionally, it is estimated that 10% of people living on Earth have warts at some point in their lives. Then we develop the most important types of warts one by one.
Of course, before that we need to make a clarification. The types of human papillomavirus are classified based on their differences in viral DNA sequence, not on their capsid-forming proteins (so we’re not talking about serotypes). Therefore, we will use a nomenclature of “HPV X” to denote each variant (eg HPV 16 or HPV 66), but it should be remembered that we are always faced with the same family of pathogens.
1. Common warts
Also known as verrucae vulgaris, these lesions are linked to infection with HPV types 2 and 4, Followed by other variants depending on the patient’s degree of immunosuppression. They are rounded papules with sharp edges, a rough surface, and a grayish color. As we said before, they can appear in any area, but the skin area of the hands is usually their favorite place.
They usually present asymptomatically, as they usually don’t cause pain, Although sometimes they cause discomfort to the patient if they are located in areas subject to weight forces (for example, in the lower part of the feet). There is little more to say, except that the occurrence of multiple or large lesions is usually related to patients with some degree of immunodeficiency (eg, organ transplants and other conditions).
2. Flat warts
This somewhat lesser-known variant of the verrucous skin lesion is caused by HPV types 3 and 10, in addition to occasional occurrences by HPV 26, 29 and 41. These are soft pink warts with a slightly scaly surface.
Its location is usually the face, the anterior area of the legs and in the scratching areas. For this reason, its nature is “autoinoculative”, that is, by physical contact with a sample infected with the virus.
Professional sources point out that although these are harmless injuries that do not cause any symptoms, their treatment and removal is complex.
3. Palmoplantar warts
They are mainly caused by HPV type 1, followed by variants 2, 3, 4, 27 and 57. These are endophytic (that is, growing inward) papules of a painful nature. As the name suggests, they occur on the soles of the feet, so their shape is flattened by the weight of the body and surrounded by cornified epithelium.
Unfortunately, this variant can be very inconvenient for the patient, as tasks such as standing or walking can be difficult for these warts to appear.
4. Genital warts
Be careful, as we are entering swampy terrain. Just as the symptomatology of the types of warts described earlier has shifted from harmless to mildly troublesome terrain, genital warts are figs from another basket. Since we got off to a good start, HPV types 16 and 18 are considered they cause over 70% of cervical cancer cases in women.
We are going further, because in 2012 the World Health Organization (WHO) estimated a total of 528,000 new cases and 266,000 deaths due to this worrying type of cancer. HPV is the cause of 12% of all female cancers in southern regions. As if that weren’t enough, studies link these types of HPV to cancers of the vulva, penis, vagina and anus.
However, sources cited above indicate that most genital HPV infections are not very problematic because in 90% of cases, they usually go away on their own within two years without associated symptoms. It should also be noted that there are other genital warts due to HPV with a low tendency to form carcinogenic processes, such as types 6 and 11.
However, persistent infection with the aforementioned oncogenic HPVs can lead to the dreaded uterine cancer. Fortunately, there are two vaccines (A bivalent and a tetravalent) that protect the general population from this type of pathogenic infection. This treatment is included in the vaccination schedules of many countries for children aged 9 to 14 years, before they start to engage in sexual activity (method of spreading this genital virus).
5. Other types and considerations
While we left the mosaic, filiform, and periungual warts types in the inkwell, we saw particular importance in focusing on the more common variant and the genital variant, as the others have an anecdotal nature of moderate epidemiological interest.
If anything we want to be clear is the multifaceted nature of human papillomaviruses, according to their differences in the DNA sequence that composes themThey can cause astronomical catastrophes such as uterine cancer or a simple skin lesion without further delay. Although this may be an insignificant problem, it is also important to note that these clinical manifestations are twice as common in people of white ethnicity and that the proportion of infection between males and females does not. shows no significant differences.
As we have seen, warts are skin lesions that close a much more complex world than one might initially expect.
Human papillomavirus types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 66 are carcinogenic to humans, while many others have relatively harmless skin lesions for the wearer. Finally, it should be noted that the most common HPV genotypes in the world are: 16, 18, 31, 33, 45, 52 and 58.
If anything we want to be clear with this digital conglomerate is this: The human papillomavirus family can range from a small skin wart to cervical cancer. not for this reason that we want to frighten readers, but to point out the variation and the epidemiological interest of this family of viruses.
- De Izaguirre d’Arellano, J., and Echezuría, L. (2011). HPV. Venezuelan Archives of Child Care and Pediatrics, 74 (4), 159-162.
- Human papillomavirus (HPV) and cervical cancer, World Health Organization (WHO). Retrieved September 12 from https://www.who.int/es/news-room/fact-sheets/detail/human-papillomavirus-(hpv)-and-cervical-cancer
- Revenga Arranz, F., and Paricio Rubio, JF (2001). The warts. Med. Integral (Ed. Impr), 395-403.
- Warts, US National Library of Medicine. Retrieved September 12, from https://medlineplus.gov/spanish/ency/article/000885.htm
- Warts, Kidshealth. Retrieved September 12 from https://kidshealth.org/es/teens/warts-esp.html
- Warts, MDSmanuals.com. Retrieved September 12, from https://www.msdmanuals.com/professional/dermatologic-disorders/viral-skin-diseases/warts