Absence of HPV in Verrucous Psoriasis Lesions

The clinical spectrum of psoriasis may be variable and verrucous lesions have rarely been observed [1]. Verrucous psoriasis is characterized by the combination of both patterns of psoriasis and verruca vulgaris [2]. To our knowledge, the involvement of human papillomavirus (HPV) in verrucous psoriasis has not been evaluated at a molecular level. Therefore, we searched the electronic pathology database of the Complejo Asistencial Universitario de Salamanca (CAUSA) for patients diagnosed with verrucous psoriasis from the 1st of January, 2012 to the 31st of December, 2023 and identified six biopsies from five patients. There were three males and two females (age range: 41−65 years). Skin biopsies revealed an epidermis with marked irregular hyperplasia, parakeratosis, hypogranulosis, papillomatosis, suprapapillary atrophy, intracorneal neutrophils and exoserosis. All these findings were considered consistent with verrucous psoriasis (Table 1, Figure 1). The presence or absence of HPV in the lesions was evaluated through DNA extraction techniques and complete genotyping real time PCR to detect and identify the specific HPV involved in the lesion. Sections were obtained from paraffin blocks. The results were negative in all cases except one, which showed presence of HPV 182. Verrucous psoriasis is a rare type of psoriasis with fewer than 40 published cases. From a clinical perspective, it is characterized by the presence of papules and verruciform hyperkeratotic plaques located in the extensor surfaces. Several clinical subtypes have been described, such as annular or unilateral verrucous psoriasis [3-5]. These lesions typically appear in patients who had been previously diagnosed with psoriasis [2]. This disease is generally diagnosed in midlife [6]. Histopathology of verrucous psoriasis is characterized by papillomatous epidermal hyperplasia without acanthosis, parakeratotic hyperkeratosis, reduced granular layer, atrophy of the suprapapillary epidermis with dilated vessels in the dermis and superficial inflammatory lymphocytic infiltrate [2]. Therefore, it is characterized by presenting psoriasiform dermo-epidermal changes, with papillomatosis as a sign that differentiates it from other clinical forms of psoriasis. There is usually presence of intracorneal neutrophil aggregates and exoserosis [2]. Differentiation between verrucous psoriasis and viral warts may be challenging. Additionally, verrucous psoriasis may be confused with verrucous carcinoma [7]. Verrucous psoriasis may resemble rupioid psoriasis in some patients [8], but the hyperkeratosis is verruciform in verrucous psoriasis and resenmobes an adhered oyster shell in rupioid psoriasis. The role of HPV in verrucous psoriasis has been ruled out through histological (H&E stains) and immunohistochemical studies, without other specifical techniques [4, 9]. Our study confirms these findings at the molecular level, since PCR and failed to identify HPV DNA in 5 of 6 biopsies of verrucous psoariasis. The identification of HPV-182 in one sample was considered incidental, since HPV-182 does not have any clinical relevance. In conclusion, verrucous psoriasis is a particular form of plaque psoriasis without any involvement by HPV in its pathogenesis. All authors discussed the results and contributed to the final manuscript. A. Santos-Briz described the histological findings. The authors have nothing to report. The authors have nothing to report. All patients in this manuscript have given written informed consent for participation in the study and the use of their de-identified, anonymized, aggregated data and their case details (including photographs) for publication. The authors declare no conflicts of interest. The authors have nothing to report.