A Case of Male Genital Psoriasis without Involvement of the Glans Penis

Abstract

Genital psoriasis is a debilitating condition affecting approximately 49% of male psoriasis patients at least once during their lifetime. This condition often presents as generalized plaque psoriasis and features well-demarcated, erythematous plaques affecting the glans penis and corona. Presentations of male genital psoriasis which disagree with this description may be under- or misdiagnosed, delaying appropriate management. We present the first reported case of chronic plaque psoriasis affecting the penile shaft without involvement of the glans. Both consistent histologic and non-cutaneous features of psoriasis facilitated diagnosis in this patient. The sclerotic plaque on the patient’s penile shaft resolved following biologic therapy for psoriasis. This rare presentation of genital psoriasis highlights important learning points for clinicians and dermatopathologists. First, genital psoriasis may affect the penile shaft without involvement of the glans penis. Second, non-cutaneous signs of psoriasis can inform diagnosis when clinical presentation is atypical. Third, psoriasis exhibits a broad spectrum of histopathology.

Adult genital psoriasis: An updated review for clinicians

“…2 There is usually involvement of the glans penis in isolation or in combination with the shaft; however, there has been one case report of genital psoriasis affecting the penile shaft without involvement of the glans. 15 Common mimics include irritant balanitis, Zoon's balanitis, penile intraepithelial neoplasia or Extramammary Paget's disease. 14 Pruritus is the most frequently reported symptom by patients and has been consistently reported as the most debilitating symptom of genital psoriasis.…”

“…It has been shown to improve genital symptoms in some patients 14,24,35 and in an unusual case of psoriasis affecting the penile shaft. 15 However, its use can be limited by adverse effects such as severe nausea with vomiting, headache and insomnia. 25 Oral dapsone (100 mg daily) has been shown to be successful in clearing psoriasis lesions within 4 weeks in one patient, without any reported adverse events.…”

“…In males, psoriatic plaques are most common on the proximal glans penis and under the prepuce for uncircumcised men, and on the glans penis and corona for circumcised men 2 . There is usually involvement of the glans penis in isolation or in combination with the shaft; however, there has been one case report of genital psoriasis affecting the penile shaft without involvement of the glans 15 . Common mimics include irritant balanitis, Zoon's balanitis, penile intraepithelial neoplasia or Extramammary Paget's disease 14 …”

“…Methotrexate is a traditional oral systemic therapy that has been widely used in clinical practice despite limited documentation in controlled trials. It has been shown to improve genital symptoms in some patients 14,24,35 and in an unusual case of psoriasis affecting the penile shaft 15 . However, its use can be limited by adverse effects such as severe nausea with vomiting, headache and insomnia 25 .…”