Sandbox:Zoon balanitis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Vishal Devarkonda, M.B.B.S[2]

Synonyms and keywords:Balanoposthite chronique circonscrite bénigne á plasmocytes, Balanitis chronica circumscripta plasmacellularis

Overview

Zoon's balanitis is an idiopathic, chronic, benign inflammatory mucositis of the genitalia. 

Historical Perspective

• In 1952, for the first time in medical literature, Zoon recognized a distinct entity in patients with chronic balanitis, named it as balanoposthite chronique circonscrite bénigne á plasmocytes” or “balanitis chronica circumscripta plasmacellularis.
• In 1954, Garnier reported the similar lesion in vulva.
• In 1956, Nikolowski described the identical lesion in oral mucosa.
• In 1963, Kortnig described the idential lesion in conjuntiva.

Classification

There is no established classification system for Zoon balanitis.

Pathophysiology

Pathogenesis

The exact pathogenesis is not clearly known, but following theories have been postulated:

• Accumlation of epithelial debris and secretions between foreskin and penis proximal to coronal sulcus, smegma, poor genital hygiene, repeated local infections, hot and humid weather results in chronic physical irritation or subclinical trauma, which in turn results in skin lesion along the lines of the trauma.
• Chronic infection with Mycobacterium smegmatis and human papillomaviruses (HPV) was found to be associated with development of Zoon balanitis.
• Many theories, which include 1) local disturbance of circulation, 2) hypersensitivity response mediated by IgE class of antibodies, 3) “extramedullary plasmacytic infiltrations that persists are expressions of occult multiple myeloma” have been postulated, no supportive evidence have been found for these hypothesis.

Histopathology

ZB has distinctive histopathological features, which include:

Epidermal

Epidermal changes include, early thickening, acanthosis and parakeratosis of epidermis, which is followed by atrophy, erosions and spongiosis.

Scattered neutrophils can be present in superficial erosions of the epidermis.

Spongiosis accentuation occurs in the lower half of the spinous zone.

Subepidermal clefts, necrotic keratinocytes, and lozenge keratinocytes can be seen in the late stages of ZB.

Dermal

Dermal changes include patchy lichenoid infiltrate of lymphocytes and plasma cells in papillary dermis, which are replaced by plasma cells, neutrophils, eosinophils, lymphocytes, and erythrocytes.

Dermal vascular dilatation with singular vertical or oblique orientation of proliferated individual vessels, is a characteristic feature of ZB.

In the later stages, upper dermis shows fibrosis which correlates well with subepidermal clefts, epidermal atrophy, and plasma cell infiltrates.

Screening

There is no established screening guidelines for Zoon balanitis