The process of aesthetic tattooing involves the implantation of pigment into the upper and middle dermis to create pictures, words, geometric patterns and other aesthetically desirable designs. Historically, tattoo-associated infection rates were much higher with common transmission and implantation of Staphylococcus and Streptococcus bacteria resulting in erysipelas, cellulitis, gangrene and sepsis. 1 Advances in sterile technique have reduced the infectious risks associated with tattooing; however, even recently there have been reports of transmission of hepatitis B, hepatitis C and human immunodeficiency virus (HIV). 1 – 3 Several cases of human papilloma virus (HPV) infections associated with tattoos have been reported. 4 – 7 It is believed that HPV infection in tattoos is attributable either to the inoculation of the area from the tattooing process or the immunomodulatory effects of the tattoo inks. Here we present a case of a 36-year-old man who developed verrucae plana within his 20-year-old tattoo. This case adds to the literature of tattoo-associated HPV infections and serves as a reminder of the risk of tattooing even with advanced sterile technique.

Initial treatment consisted of one cycle of light liquid nitrogen cryotherapy directed at two test areas. Unfortunately, this did not result in clinical improvement and a slight scale developed in the treated areas. Topical treatments such as 5% 5-fluorouracil or 5% imiquimod were offered as the next option while informing the patient that these treatments may affect the integrity of the tattoo colour. The patient did not return for follow-up and no further treatments were provided.

A biopsy was taken from the right forearm and sent for histopathological examination. Histopathology revealed keratinocytes with HPV-induced changes and a diagnosis of verrucae planae was made by the pathologist ( Figure 2 ). The hematoxylin and eosin (H&E) stained slides revealed an epidermis with orthokeratosis, papillomatosis, areas of hypergranulosis and pathognomonic koilocytes. The black tattoo ink was identified in the dermis below the verrucae. Given the diagnosis of verrucae planae associated with tattoo, therapy would have to be tailored to this very unique clinical situation taking into consideration the effects of therapeutics on the tattoo ink.

This 36-year-old man presented with a 6-month history of skin-coloured flat-topped papules within a black coloured tattoo ( Figure 1 ). The tattoos over the arms and forearms were applied over 20 years prior by a professional tattoo artist and there was no previous history of cutaneous eruptions within the tattoos. The skin-coloured papules presented suddenly with no associated symptoms. The number of papules within the tattoo had been increasing from the initial time of onset. Hundreds of papules were present at the time of presentation. The patient had no other medical conditions and was not taking any prescription medications. There was a dermatologic history of atopic dermatitis for which topical corticosteroids were used for occasional flares. There was no history of cigarette smoking or intravenous drug use. Full cutaneous examination did not reveal the presence of these skin-coloured flat-topped papules anywhere on the body apart from the tattooed areas of the right forearm and arm. All laboratory investigations were normal including negative tests for HIV and hepatitis. The differential diagnosis included lichen nitidus, papular eczema, papular sarcoidosis, lichen planus and verrucae planae.

Discussion

The prevalence of tattoos in the general population is estimated at 15% to 25% with a higher prevalence among younger men and women.8,9 As the population of tattooed men and women grow, there have been a growing number of reports of complications associated with tattoos.1,8,9 By far the most common reactions to tattoos are the inflammatory reactions. These inflammatory reactions range from koebnerization of existing inflammatory conditions to allergic reactions against components of the tattoo. Less likely, but perhaps more important, are the risks of infection associated with tattoos. Tattoos have been associated with the transmission of HIV, hepatitis B, hepatitis C, syphilis, tuberculosis, leprosy and other mycobacteria infections.1 There have also been several reports HPV infections associated with tattoos.4,5,10 In particular, it appears that black tattoo ink has a higher risk of verrucae development and HPV infection.7

Here we present a case of tattoo-associated verrucae planae or flat warts that developed over 20 years from the time of initial tattooing. Verrucae planae are usually caused by HPV-3, -10, -28 and -49 and have a predilection for the face, larynx and hands. They normally present as white/pink to skin-coloured flat-topped papules. The mechanism by which HPV localizes to the tattoo may involve either traumatic implantation of HPV during the tattoo process or the contamination of the tattoo inks or instruments or by localized immunosuppression that occurs secondary to the tattoo ink. Prior to this case, the longest latency period between tattooing and the development of HPV infection had been 10 years.5 In general, there is a long latency period between tattooing and the manifestations of the HPV infection. The mean latency period is about 5 years. This suggests that the immune system is able to control the infection, and that some immune system perturbation likely results in the development of clinical disease. In one case report, exposure to sunlight resulted in the development of verrucae two and half years after tattooing.10 The patient presented here did not identify any events that may have contributed to the development of verrucae planae.

The main treatment options for verrucae planae involve the use of topical 5% 5-fluorouracil or 5% imiquimod.11,12 The success of these treatments in tattoo-associated verrucae has been limited perhaps due to the deeper implantation of the virus. In addition, there is evidence that some of these topical treatments, particularly imiquimod, may affect the aesthetics of the tattoo.13,14 Other topical treatments that can be considered for verrucae planae include 10% salicyclic acid, 10%–30% glycolic acid and 0.025%–0.05% tretinoin.12 There have also been reports of successful treatment of warts in tattoos with squaric acid dibutylester that did not disrupt the integrity of the tattoo.15 Destructive treatment options such as ablative laser, curetting or surgical excision may also be considered but these modalities may cause significant damage to the tattoo and may result in scarring. In our case, a trial of liquid nitrogen cryotherapy did not result in any significant clinical improvement and superficial scale developed in the areas treated.

In summary, we present a case of verrucae planae associated with a tattoo after a long latency period of more than 20 years. This long-term infectious risk needs to be communicated to patients considering tattoos, as treatment options often have limited efficacy and may negatively impact the aesthetics of the tattoo.