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Year : 2021  |  Volume : 9  |  Issue : 4  |  Page : 156-158

The curious case of an erythematous plaque on penis

People’s College of Medical Sciences and Research Center Bhopal, HIG A6, PCMS Campus, Bhopal, Madhya Pradesh, India

Date of Submission15-Dec-2021
Date of Decision18-Dec-2021
Date of Acceptance21-Jan-2022
Date of Web Publication15-Jul-2022

Correspondence Address:
Prachi R Srivastava
People’s College of Medical Sciences and Research Center Bhopal, HIG A6, PCMS Campus, Bhopal, Madhya Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/dypj.DYPJ_77_21

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Penile psoriasis is a rare entity comprising of only 3% of all the psoriatic cases. However, it is one of the most common non-venereal diseases of the genitalia. Due to the location, sexually transmitted diseases are often suspected as the first diagnosis leading to delay in diagnosis and therapy. This causes quality of life impairment of patients along with severe psychosocial disturbances. We hereby present the case of a young immunocompetent male patient with a non-healing lesion on the glans penis of 4 month duration with raised anti-herpes simplex virus 2 immunoglobulin G (IgG) and IgM titres who was previously misdiagnosed as herpes genitalis owing to the location and serology. A biopsy leads to the correct diagnosis of psoriasis. He was then treated with calcipotriol and clobetasol combination with which the lesions healed in a week. We are presenting this case to raise the index of suspicion of psoriasis in patients with isolated penile lesions, as the presentation here is different with the lesions being non-scaly, compared to the other areas of the body. Another aspect is that maybe this case represents Wolf’s isotopic response in relation with “Zoster Sine Herpete” and psoriasis. This is to our knowledge the first time this phenomenon is being reported with psoriasis..

Keywords: Calcipotriol with clobetasol, genital psoriasis, isolated penile psoriasis, penile psoriasis

How to cite this article:
Srivastava PR, Argal D, Vyas P, Saxena A, Dey VK. The curious case of an erythematous plaque on penis. D Y Patil J Health Sci 2021;9:156-8

How to cite this URL:
Srivastava PR, Argal D, Vyas P, Saxena A, Dey VK. The curious case of an erythematous plaque on penis. D Y Patil J Health Sci [serial online] 2021 [cited 2022 Aug 8];9:156-8. Available from: http://www.dypatiljhs.com/text.asp?2021/9/4/156/351087

  Introduction Top

Psoriasis is a chronic, inflammatory papulosquamous disease with a worldwide prevalence of about 2%; however, isolated penile involvement is seen in only 3% of all psoriasis cases. The commonest site of involvement is the scrotum, glans, corona, and prepuce in that order.[1] The etiology of genital psoriasis is still unknown, and further studies are needed for clarification. However, it involves an alteration of CD4+ and CD8+ cells along with anomalous proliferation and differentiation of keratinocytes.[2]

We hereby present the case of a 25-year-old male with a single, non-healing erythematous plaque on the glans penis with 4-month duration.

  Case Report Top

A 25-year-old unmarried male patient presented to us with a 4-month history of a single erythematous lesion over the glans penis, which was asymptomatic and gradually increasing in size. The patient denied any sexual exposure and did not have a history of similar lesions in the past. On examination, the patient was uncircumcised and had a single erythematous lesion of 2 × 1.7 cm on the dorsal surface of the glans penis [Figure 1]. There was no lymphadenopathy and no lesions elsewhere on the body. Due to the long-standing history of genital lesion, we did serology for immunoglobulin G (IgG) and immunoglobulin M (IgM) HSV 2, which came positive with an IgG level of 15.8 (0.9–1.09) and IgM level of 3.36 (0.8–1.1). Venereal Disease Research Laboratory and enzyme-linked immunosorbent assay for HIV were negative. The patient was started on tablet valacyclovir 1 g thrice daily and topical fusidic acid. When the patient was followed up after 2 weeks, the lesion had increased in size to 2.5 × 2 cm. A 2 mm punch biopsy was then done with a differential of Zoon’s balanitis. The biopsy showed typical psoriatic changes with rete elongation, exocytosis of lymphocytes, capillary dilation, and neutrophilic microabcesses, which gave the final diagnosis of isolated penile psoriasis [Figure 2]. He was started on topical calcipotriol and clobetasol therapy for 2 weeks, which led to complete resolution of the lesion [Figure 3]. The patient is on regular follow-up since a month and is currently symptom-free on maintenance with plain calcipotriol ointment and emollients.
Figure 1: Single, well-defined erythematous plaque over dorsal surface of glans penis

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Figure 2: Histopathology showing parakeratosis, rete elongation, neutrophilic microabscesses, and capillary dilatation (40X)

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Figure 3: Complete resolution of the lesion

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  Discussion Top

Genital psoriasis is a rare disease and causes a significant impact on the psychosexual well-being of the patient. Further, because of the location, it is often misdiagnosed leading to a delay in treatment. It may be localized to the genitals or may occur as a part of plaque psoriasis with 29–40% patients having genital involvement. It frequently occurs as a part of inverse psoriasis with 79.2% patients having genital involvement.[3] It is hence important to include examination of the genital region in daily clinical practice.

The etiology of genital psoriasis not known, and studies are needed for further clarification. However, as treatment for psoriasis vulgaris is also effective for genital psoriasis, it seems to have a pathophysiology similar to plaque psoriasis in other skin zones. There is an alteration in the activation of CD4+ and CD8+ T-cells and abnormal proliferation and differentiation of keratinocytes. It is still not understood as to what causes the disease to commence in this particular area; there may be Koebner’s phenomenon due to constant local mechanical and chemical irritation.[4] Our patient had raised IgG and IgM titers but did not have signs or symptoms of genital herpes, maybe it was “zoster sine herpete” and the psoriatic lesion presenting there was a part of wolf’s isotopic response.[5] This phenomenon has been hitherto unreported with psoriasis, and maybe this is the first case to demonstrate that.

Clinically, the lesions are well-demarcated, brightly erythematous, thin plaques that lack the typical scaling due to maceration; however, circumcised males tend to have scalier lesions. There may be overlying raghades and fissures which cause soreness and pain. A case of isolated pustular psoriasis on the penis has been reported.[6]

The patients may experience pruritus and burning, which may be further aggravated by irritation from urine and feces, tight-fitting clothes, and sexual intercourse.[1],[2]

There is no histopathological difference between the genital and non-genital lesions, except that parakeratosis is normally present in the stratum corneum of genital skin. Classical histopathological characteristics of non-genital plaque psoriasis such as hyperkeratosis, hypogranulosis, Kogoj’s and Munro’s microabcesses, thickening of the Malpighian layer, parakeratosis, and elongation of the rete ridges are seen.[1] Histopathology was instrumental in bringing to light the diagnosis in this case, thereby re-establishing the importance of biopsy in difficult to diagnose cases. There should be no hesitation in performing genital biopsies as the presentation in this area is often morphologically different, thereby making the diagnosis disconcerting.

Evidence-based recommendations for the treatment of genital psoriasis include the use of short-term corticosteroids as a first-line treatment option, which can be combined with vitamin D analogs, which was done in our patient. The genital skin is thinner and more vulnerable with increased penetrability of topical applications. Mild topical tar preparations are the second-line options. The use of topical immunomodulator agents, such as tacrolimus gel 0.1% or pimecrolimus cream 1%, has shown benefits for long-term therapies. Suspected concurrent bacterial or fungal infections should be managed concomitantly. Anthralin, tazarotene, and UV light are usually avoided in the genital area.[2],[7],[8] Ixekizumab has been recently reported as an effective biologic therapy for isolated penile psoriasis.[9],[10]

We are presenting this case for its rarity and to re-enforce the importance of performing genital biopsy in difficult to diagnose cases. We would like to conclude by stressing upon the consideration of genital psoriasis as a differential for long-standing erythematous lesions over the genital area.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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  References Top

Meeuwis KA, de Hullu JA, Massuger LF, van de Kerkhof PC, van Rossum MM Genital psoriasis: A systematic literature review on this hidden skin disease. Acta Derm Venereol 2011;91:5-11.  Back to cited text no. 1
Guglielmetti A, Conlledo R, Bedoya J, Ianiszewski F, Correa J Inverse psoriasis involving genital skin folds: Successful therapy with dapsone. Dermatol Ther (Heidelb) 2012;2:15.  Back to cited text no. 2
Dogra S, Yadav S Psoriasis in India: Prevalence and pattern. Indian J Dermatol Venereol Leprol 2010;76:595-601.  Back to cited text no. 3
Krueger JG, Bowcock A Psoriasis pathophysiology: Current concepts of pathogenesis. Ann Rheum Dis 2005;64 (Suppl. 2):ii30-6.  Back to cited text no. 4
Madke B, Doshi B, Pande S, Khopkar U Phenomena in dermatology. Indian J Dermatol Venereol Leprol 2011;77:264-75.  Back to cited text no. 5
Singh N, Thappa DM Circinate pustular psoriasis localized to glans penis mimicking “circinate balanitis” and responsive to dapsone. Indian J Dermatol Venereol Leprol 2008;74:388-9.  Back to cited text no. 6
Buechner SA Common skin disorders of the penis. BJU Int 2002;90:498-506.  Back to cited text no. 7
Goldman BD Common dermatoses of the male genitalia. Recognition of differences in genital rashes and lesions is essential and attainable. Postgrad Med 2000;108:89-91, 95-6.  Back to cited text no. 8
Caroline Helwick C. October 31, 2017. Ixekizumab effective for genital psoriasis, improves sexual health. Available from: https://www.medscape.com/viewarticle/887839. [Last accessed on 2020 Oct 12].  Back to cited text no. 9
Eli Lilly and Company. March 24, 2016. A study of ixekizumab (LY2439821) in participants with moderate-to-severe genital psoriasis (IXORA-Q). Available from: https://clinicaltrials.gov/ct2/show/NCT02718898. [Last accessed on 2020 Oct 12].  Back to cited text no. 10


  [Figure 1], [Figure 2], [Figure 3]


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