Diagnosis: Zoon’s balanitis
We ordered a biopsy because we suspected that the cause of the rash was either erythroplasia of Queyrat (a premalignant condition also known as Bowen’s disease of the glans penis) or Zoon’s balanitis (plasma cell balanitis or balanitis circumscripta plasmacellularis). The biopsy report confirmed the diagnosis of Zoon’s balanitis and showed no signs of malignancy. The features of Zoon’s balanitis include epidermal atrophy, loss of rete ridges, spongiosis, and subepidermal plasma cell infiltrate without evidence of malignancy (FIGURE 2).
FIGURE 2
Dense plasmacytic infiltration underlying the mucosal epidermis
Condition affects older, uncircumcised men
Zoon’s balanitis is thought to be a benign condition that typically affects uncircumcised middle-aged to elderly men.1,2 Worldwide prevalence among uncircumcised men is approximately 3%.2 The etiology is unknown; it’s thought that this condition may be caused by friction, trauma, heat, lack of hygiene, exogenous or infectious agents, an IgE hypersensitivity, or a chronic infection with Mycobacterium smegmatis.1,2
Typically, the appearance of the lesion precedes diagnosis by about one to 2 years.1 The patient usually complains of mild pruritus and tenderness. Undergarments may be bloodstained.
The differential for penile lesions is extensive, and includes psoriasis, nummular eczema, candidiasis, herpes simplex, scabies, lichen sclerosus et atrophicus or lichen planus, syphilis, balanitis, and erythroplasia of Queyrat.
The lesion associated with Zoon’s balanitis is a solitary, glistening, shiny, red-to-orange plaque of the glans penis or prepuce of an uncircumcised male. Pinpoint erythematous spots or “cayenne pepper spots” may also be associated with this condition.
Patients with erythroplasia of Queyrat have either a solitary or multiple nonhealing erythematous plaques on the glans penis. These lesions may also affect the adjacent mucosal epithelium. As is true with Zoon’s balanitis, the typical patient is uncircumcised and middle-aged to elderly.1,2