Infection with human papillomavirus (HPV) may cause widespread erythematous squamous plaques. Psoriasis and HPV are likely to be related pathophysiologically.

A 69-year-old male complained of whitish eruptions on his arms and both sides of his trunk. 

The patient had a history of psoriasis, and the newer eruptions seemed to have developed at the same site as his former psoriatic plaques.

On examination, multiple lesions appeared like spiny whitish papules, similar to viral warts.  

This elderly patient was successfully treated with weekly doses of subcutaneously injected systemic methotrexate and oral folic acid. The outcome was satisfactory and the lesions subsided within 6 weeks of treatment.

Source: Matheu KP, Gallegos NPL, Álvarez SAP. Human papillomavirus within psoriasis plaques in a patient with psoriasis: a case report. Int J Dermatol Venereol. January 19, 2022. DOI: 10.1097/JD9.0000000000000224.