Indian Journal of Dermatology
: 2015  |  Volume : 60  |  Issue : 3  |  Page : 314--315

Genital porokeratosis: A distinct clinical variant?

Urmi Khanna, Paschal D'Souza, Tapan Kumar Dhali 
 Department of Dermatology ESIPGIMSR Basaidarapur, New Delhi, India

Correspondence Address:
Paschal D«SQ»Souza
Department of Dermatology ESIPGIMSR Basaidarapur, New Delhi

How to cite this article:
Khanna U, D'Souza P, Dhali TK. Genital porokeratosis: A distinct clinical variant?.Indian J Dermatol 2015;60:314-315

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Khanna U, D'Souza P, Dhali TK. Genital porokeratosis: A distinct clinical variant?. Indian J Dermatol [serial online] 2015 [cited 2021 Sep 19 ];60:314-315
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Porokeratosis (PK) is a primary disorder of epidermal keratinization which presents with typical annular lesions with a hyperkeratotic raised border. The localized variants include classic PK of Mibelli, linear PK, and punctate PK. [1] PK of the genitalia is a rare entity with most cases reported in the 4 th -5 th decade. It has traditionally been included within porokeratosis of Mibelli or as a plaque form, although most published cases share some differential characteristics that suggest defining genital PK as a distinct clinical variant. [2] A 22-year-old married man presented with multiple pruritic lesions over scrotum since 4 years. They began as lentil sized lesions 4 years back and progressed in size and number spreading to involve the penis since 6 months. There was no response to various topical medicaments including steroids and antifungals. There was no family history of similar complaints and no history suggestive of immunosuppression. Cutaneous examination revealed multiple well-defined skin colored scaly annular plaques approximately 6 to 14 mm in diameter present over the scrotum and shaft of penis with a slightly depressed center surrounded by a peripheral hyperkeratotic ridge [Figure 1]. On stretching the skin the peripheral ridge revealed a circumferential furrow which was further delineated by performing the ink test using gentian violet stain [Figure 2]. Examination of the perianal, gluteal cleft and groin was within normal limits. With the differential diagnosis of PK, lichen planus, granuloma annulare and psoriasis a punch biopsy was taken from the raised peripheral edge. Routine investigations revealed no abnormality. Hematoxylin and eosin staining of the biopsy specimen showed the presence of cornoid lamella [Figure 3]. A diagnosis of porokeratosis was established.3 The patient was started on capsule isotretinoin 20 mg once a day and twice daily application of fluticasone propionate cream. At 6 weeks follow up the pruritus had decreased and there was slight flattening of the annular plaques [Figure 4]. Although PK can nearly involve any area of the body, genital PK is considered extremely rare. Genital PK has traditionally been included within porokeratosis of Mibelli and its true incidence is still undetermined. Repeated trauma (friction or scratching) might explain a part of pathogenesis. [1] Chen et al.[1] compiled all 11 published cases of porokeratosis confined to the genitalia and found all cases were described only in men except for 1 case reported in the natal cleft of a female. Three cases were associated with itching, one case had decreased CD4/CD8 without HIV and no malignant transformation was found In any of the reported cases. The authors postulated that these aforementioned features differentiate PK localized to genitalia from PKM. [1] Several therapeutic options have been described, such as cryotherapy, CO 2 laser therapy, oral retinoids, and topical treatment with vitamin D 3 analogues, keratolytic agents, 5-fluorouracil under occlusion, and, more recently, imiquimod under occlusion, and photodynamic therapy, with variable results. [2] The presence of multiple scaly annular pruritic plaques localized to the genitalia in a young male made a diagnosis of papulosquamous disorders a likely possibility. However, a positive ink test with presence of characteristic cornoid lamella on histopathology confirmed a diagnosis of porokeratosis. We report this case to suggest consideration of genital porokeratosis as a distinct clinical entity and its inclusion in the list of differential diagnosis of annular plaques localized to the genitalia. Additionally, due to paucity of data regarding the risk of malignant transformation in this entity, regularfollow up of these patients is warranted.[3]{Figure 1}{Figure 2}{Figure 3}{Figure 4}


1Schamroth JM, Zlotogorski A, Gilead L. Porokeratosis of Mibelli. Overview and review of the literature. Acta Derm Venereol 1997;77:207-13.
2Chen TJ, Chou YC, Chen CH, Kuo TT, Hong HS. Genital porokeratosis: A series of 10 patients and review of the literature. Br J Dermatol 2006;155:325-9.
3Valdivielso-Ramos M. Genital Porokeratosis. Actas Dermosifiliogr 2008;99:217-20.