Warts are caused by the Human Papillomavirus (HPV), a common viral infection, not the Human Immunodeficiency Virus (HIV) itself. Warts develop when the body’s immune system fails to clear the HPV infection. HIV progressively weakens the immune system by depleting CD4+ T-cells, which are crucial for controlling viral infections like HPV. This compromised state allows HPV to become more frequent, persistent, and aggressive, leading to numerous or unusually located warts. The term “HIV warts” refers to HPV warts in individuals whose immune suppression dictates the severity and location of the lesions.
The Primary Locations of HPV Warts
In the general population, warts typically appear in specific areas dictated by the HPV strain involved. Common warts, known medically as verruca vulgaris, frequently manifest on the hands, fingers, and around the nails, often presenting as rough, raised, dome-shaped growths. These are usually caused by HPV types 2 and 4.
Plantar warts develop on the soles of the feet, and unlike common warts, they tend to grow inward, often causing pain with walking or standing. They can sometimes appear in clusters, referred to as mosaic warts. Flat warts (verruca plana) are much smoother, smaller, and flatter than other types, appearing on the face, arms, or legs, and may occur in large numbers.
Genital warts (condylomata acuminata) are the most common sexually transmitted type, typically caused by low-risk HPV types 6 and 11. These lesions appear on the external genitalia, the penile shaft, the vulva, and in the perianal and anal canal regions. They can also occur on internal mucosal surfaces, such as the cervix, vagina, urethra, and mouth and throat.
Unique Manifestations in Immunocompromised Individuals
For individuals with HIV, the profound immune suppression can dramatically change the presentation of HPV warts, extending their reach to atypical locations. Warts may become widespread over the body, presenting as numerous, clustered lesions known as widespread verrucae. This includes the frequent appearance of genital-associated HPV types, like HPV 6 and 11, on extragenital sites such as the hands, feet, and face.
The lesions often grow to an unusually large size, sometimes forming giant condylomata, and may exhibit excessive thickening of the skin (hyperkeratosis). HPV infections in this population may involve mucosal surfaces beyond the anogenital area, including the conjunctival, nasal, oral, and laryngeal regions. These warts are highly persistent and resistant to standard treatments, often leading to frequent recurrence.
The risk of malignant transformation is significantly higher, particularly with high-risk HPV types such as 16 and 18. These oncogenic types can cause high-grade precancerous lesions, especially in the anal canal, which is a concern for people with HIV. The presence of multiple HPV types within a single lesion is also more common, reflecting the immune system’s failure to control the viruses.
Distinguishing Warts from Other Skin Conditions
HIV disease increases susceptibility to numerous skin infections, making it important to distinguish HPV warts from other similar lesions. Molluscum contagiosum, a highly contagious viral skin infection, is frequently seen in people with HIV. These lesions are smooth, dome-shaped papules that are pink or flesh-colored, often exhibiting a small central indentation, unlike the rough, cauliflower-like surface of many warts.
Another serious condition that can be mistaken for warts is Kaposi’s Sarcoma (KS), a cancer caused by Human Herpesvirus 8 (HHV-8). KS lesions are typically dark and vascular, appearing as red, purple, or brown patches, plaques, or nodules. Unlike a bruise, these lesions do not blanch (whiten) when pressed, which is a distinguishing feature from the appearance of a wart.
Fungal infections, such as tinea, can also present with atypical or severe features in an immunocompromised person, sometimes mimicking the appearance of flat warts. However, tinea often presents with scaling and itching, and it is usually diagnosed with a simple skin scraping. Any atypical, pigmented, bleeding, or rapidly growing lesion should be promptly evaluated, as these features may indicate a more serious underlying issue.