PSD02 Where the sun don’t shine: a rare case of genital lupus erythematosus

Abstract Cutaneous lupus erythematous (LE) encompasses several different phenotypic presentations that may or may not occur in the presence of systemic LE. Ultraviolet radiation is a well-documented exacerbating factor. Involvement of nonphotosensitive sites such as the oral mucosa and acral sites is common and has been reported. However, genital involvement is exceedingly rare, and to date there have been only 10 published cases of LE affecting the genitalia, of which nine were in women. Herein, we report a case of severe genital lupus affecting the glans penis. A 54-year-old male patient had been attending our clinic for a number of years with recalcitrant discoid LE, requiring a combination of second-line systemic therapy and superpotent topical steroids. He had a background history significant for hypospadias, for which he had undergone correctional surgery at age 3 years. Four years after his initial presentation with discoid lupus, he reported a persistent erosion on his glans penis. On examination, there was an erythematous eroded plaque affecting the glans penis, proximal to the urethral opening. A skin biopsy revealed atrophic skin with hyperkeratosis, parakeratosis with scale crust, and underlying interface changes, consistent with lupus erythematosus. Concurrently, he started to develop recurrent urinary tract infections, requiring repeated courses of antibiotics in the community, culminating in multiresistant extended-spectrum beta-lactamase infections. He is currently attending urology and is under consideration for circumcision and intravesical antibiotics should he continue to develop urinary tract infections. In addition to hydroxychloroquine and mycophenolate mofetil, therapy directed at genital involvement with mepacrine and superpotent topical steroid under occlusion was initiated with good response. Of the 10 purported cases of genital lupus, four had a diagnosis of systemic LE and six had a background of discoid LE, as was the case with our patient. The pathogenesis is not currently well understood. Previous studies found no differences in cytokine expression between sun-exposed and sun-protected sites, suggesting that while ultraviolet exposure plays a role in the induction of skin lesions, other intrinsic mechanisms may affect both sites. As for genital involvement in LE, it has been postulated that the Koebner phenomenon may play an important role. Clinical presentations vary, ranging from atrophic dyspigmented plaques and lichen planus-like lacy reticular plaques to erosion or ulceration of the genital mucosa. The diverse morphological presentations of genital lupus can complicate or delay diagnosis. Important differentials to consider include herpes simplex, squamous cell carcinoma and sexually transmitted disease. Early diagnosis and treatment are key to avoiding scarring and disfigurement.