Introduction
Human papillomaviruses are DNA (deoxyribonucleic acid) viruses that are double-stranded and non-enveloped. Human papillomaviruses infect the skin or mucous membrane and cause multiple epithelial lesions and cancers. More than 100 subtypes of human papillomavirus have been identified. HPV infections are the common cause of sexually transmitted diseases. HPV infection causes warts and various types of cancers.
What Is Human Papillomavirus Infection?
Human papillomavirus infection is a viral infection that affects the skin or mucous membranes. It causes epithelial lesions and cancers on cutaneous and mucosal surfaces. Various subtypes of HPV are present. Individuals with multiple sexual partners are at high risk for infection with HPV subtypes.
HPV infection can be classified into:
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Cutaneous.
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Mucosal or anogenital.
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Epidermodysplasia verruciformis.
HPV infection increases the risk of laryngeal, oral, anogenital, mouth, tonsils, throat, and lung cancer. Subtypes 1, 2, 4, 27, or 57 cause cutaneous warts of hands and feet, known as verruca vulgaris and verruca plantaris. Subtypes 6 and 11 cause low-risk infections like condylomata formation and low-grade precancerous lesions. They are responsible for juvenile and adult recurrent respiratory papillomatosis.
Subtypes 16 and subtype 18 cause high-risk infections like high-grade intraepithelial lesions that can cause malignancies. Male and female anogenital cancers, oropharyngeal cancers, and precancerous and cancerous lesions of the cervix. HPV 16 is the main causative agent for HPV-positive oropharyngeal cancers. HPV infection does not cause cancer in isolation. However, triggered by factors like folate deficiency, pregnancy, smoking, UV (ultraviolet) light exposure, and immunosuppression.
How Does Human Papillomavirus Infection Occur?
Human papillomavirus spreads via direct skin-to-skin contact and vaginal or anal sexual methods. It also spreads from a pregnant mother to the baby. The virus integrates at the weak sites in the DNA. The virus disrupts the skin or mucous membranes and enters the epithelium to infect the basal stem cells. The infected cells mature, and the production of the virion is increased. An increase in virion production in the infected tissue is manifested as hypertrophy with the potential for malignant transformation and atypia.
What Are the Signs and Symptoms of Human Papillomavirus Infection?
The signs and symptoms associated with HPV infections are:
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Common Warts - They are raised above the skin with a cauliflower-like surface. It can be seen on the hands and feet and elbows or knees.
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Plantar Warts - They are seen on the soles of the feet. They cause pain while walking because of their inward growth pattern.
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Subungual or Periungual Warts - These types of warts are found under the fingernail, around the fingernail, or on the cuticle, and treatment for these types of warts is challenging because of their location.
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Flat Warts - They are seen on the arms, face, or forehead. They are not associated with cancer in individuals with normal immune function.
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Genital Warts - They are due to sexually transmitted infections. They are known as condylomata acuminata or venereal warts and are different from warts that occur on other parts of the body.
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Laryngeal Papillomatosis - Laryngeal papillomatosis causes the formation of warts on the larynx or other regions of the respiratory tract.
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Cancers - HPV infection causes squamous cell carcinoma of the skin, skin cancer, cervical cancer, anal cancer, penile cancer, head and neck cancer, and lung cancer.
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Anal Dysplasia - Anal dysplasia is a precancerous condition that affects the lining of the anal canal. It may cause lumps in and around the anus.
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Epidermodysplasia Verruciformis - It is a rare autosomal recessive hereditary skin disorder that causes the growth of macules and papules on the hands and feet, which resembles tree bark.
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Focal Epithelial Hyperplasia - It is a benign neoplastic condition that causes multiple white to pink papules in the oral cavity.
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Mouth Papillomas - Papilloma is a benign epithelial tumor with nipple-like growth and finger-like fronds.
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Verrucous Cyst - Verrucous cysts are cutaneous cysts similar to epidermoid cysts. However, the lining shows the presence of papillomatosis.
What Are the Complications of Human Papillomavirus Infection?
Human papillomavirus infection causes oral and upper respiratory lesions like tongue, tonsils, soft palate, nose, or laryngeal lesions. Certain subtypes of HPV cause cancers in the cervix, anus, mouth, and upper respiratory tract. They contribute to the formation of cancers by causing mitotic changes in the cell. Complications like urethral obstruction occur due to the presence of genital warts. Condylomata form ulcers and get infected. Complications like poor cosmesis and progression to malignancy also occur.
How Is Human Papillomavirus Infection Diagnosed?
The diagnosis is based on the history, clinical examination, and the following tests:
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Pap Smear Test - Women above 30 years of age, should be tested with the HPV test and pap test every five years to diagnose cervical cancer.
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HPV Test - HPV tests are performed to identify high-risk strains of the virus that cause cervical cancer.
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Acetic Acid Solution Test - This test is performed to identify difficult-to-see flat lesions where a vinegar solution is applied to HPV-infected areas on the genital region. The affected areas turn white.
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Biopsy - A biopsy of cancerous cells is taken, and a histopathological examination is done to identify the presence of HPV infection.
How Is Human Papillomavirus Infection Treated?
The following procedures are done to treat human papillomavirus infection. This include:
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Medications - Medications like salicylic acid are given to treat warts. Podofilox and trichloroacetic acid creams are given to treat warts.
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Surgical Procedures - Surgical procedures like surgical removal, laser surgery, cryotherapy (freezing with liquid nitrogen), electrocautery (burning with an electric current), loop electrosurgical excision procedure, or cold knife cone excision procedures are performed to resect the persistent cervical dysplasia at cervical os and transformation zone.
According to CDC (centers for disease control) guidelines, boys and girls between 11 to 12 years of age should be vaccinated for HPV, women should get vaccinated through the age of 26, and men at 21 years of age.
Conclusion
Human papillomavirus infection is an infectious disease that affects the skin or mucous membrane. Some strains of HPV are responsible for various types of cancers. Some strains cause skin or mucous membrane lesions. It is important to diagnose early and receive proper treatment. It is sexually transmitted. Hence, multiple sexual partners should be avoided. Timely screening for HPV and vaccinations are essential to prevent the infection.