Zoon’s Vulvitis: A case report

Zoon’s vulvitis or plasma cell vulvitis (PCV) is a rare, benign inflammatory condition of the vulvar mucosa [1]. PCV can present with an asymptomatic lesion, or can cause discomfort, dyspareunia and pruritus [2]. In this way, PCV can mimic other lesions of the vulval mucosa, such as lichen planus.

Purpose of study and study design

Due to the rarity of this condition, incidence is not well documented and treatment is based on previous case studies. No RCTs exist to investigate optimum management and no management guidelines exist. Most case studies report using topical steroids [3], however some reports trialled immunological therapies, namely tacrolimus [4]. Further case studies of this rare condition may improve treatment and management. Malignant potential of this condition has also not been documented or observed. This is unlike Zoon’s balantitis – a benign inflammatory condition of the penile mucosa. Further case reports, will allow the pathophysiology and natural history of the condition to be better understood.

This was a retrospective review of patient’s chart and histology results.

This is the case of a 60 years menopausal lady. She was referred to the GOPD clinic, with a history of vulval discomfort. On examination, a small area of ulceration was observed on the left labia, measuring approximately 10 x 10 x 10 mm in size. Biopsy showed; focal spongiosis of the epidermis, lymphocytic and neutrophilic exocytosis with mixed inflammatory cell infiltration of the underlying dermis - in keeping with a diagnosis of PCV.

Our patient was treated with topical 2% hydrocortisone cream and discharged from the gynaecology outpatient clinic. She was asymptomatic on discharge.

Pathophysiology is not yet fully understood, however the condition is thought to be idiopathic [4], with some evidence that this may be secondary to trauma or infection [5]. While it is known to be a benign condition, malignant changes have not yet been reported [5], this is unlike Zoon’s balantitis where malignant change has been observed [6]. Diagnosis is primary histological, with plasma cell infiltrate being predominant [7]. Vascular proliferation with haemosiderin deposits may also be observed. While the clinical presentation and diagnosis of plasma cell vulvitis is well described across case studies, optimum treatment has not yet been defined. Within the literature, treatments trialed include immunosuppressive agents such as imiquimod or tacrolimus, surgical resection, and similar to our case study, corticosteroids. Further case studies of this rare condition may improve treatment and management of same. Furthermore, ongoing publication of case reports of Zoon’s vulvitis, as well as follow up of same are needed in order to completely understand the natural history of the disease and exclude malignant potential.

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6. dos Reis HL, de Vargas PR, Lucas E, Camporez T, Ferreira D de C. Zoon vulvitis as a differential diagnosis in an HIV-infected patient: a short report. J Int Assoc Provid AIDS Care. 2013; 12: 159–161. PubMed: https://www.ncbi.nlm.nih.gov/pubmed/23449712
7. Joshi UY. Carcinoma of the penis preceded by Zoon's balanitis. Int J STD AIDS. 1999; 10: 823–825. PubMed: https://www.ncbi.nlm.nih.gov/pubmed/10639067