Derm Dx: Itchy, discolored genitalia

Balanitis xerotica obliterans (BXO) is a subtype of Lichen sclerosus (LS), a chronic inflammatory disease of the skin and mucosa. BXO affects the anogenital region in males, and is usually confined to the foreskin and glans of the penis. Symptoms...

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Balanitis xerotica obliterans (BXO) is a subtype of Lichen sclerosus (LS), a chronic inflammatory disease of the skin and mucosa. BXO affects the anogenital region in males, and is usually confined to the foreskin and glans of the penis.

Symptoms are often chronic because of delay in diagnosis, and patients with BXO require long-term evaluation due to risk of scarring and developing squamous cell carcinoma (SCC). Although BXO occurs in all races, whites appear to be preferentially affected. BXO can present from childhood to old age.

The pathogenesis of BXO is unclear. There are reports of familial cases.  An association with other autoimmune disorders such as thyroid disease, vitiligo, and morphea has also been reported.

BXO presents with atrophic lesions that are hypopigmented or depigmented, resembling vitiligo. BXO most commonly occurs on the foreskin and glans of the penis, but may extend on to the penile shaft and scrotum.

If the glans is involved, hemorrhage is common and shallow erosions may occur. BXO of the glans does not result in nonhealing erosions, but rather simply skin fragility.

Most men with BXO are uncircumcised, and like women with LS who develop narrowing of the introitus, men with BXO may develop phimosis, a condition in males where the foreskin cannot be fully retracted over the penis. Many men with BXO many eventually require circumcision.

Unlike lichen sclerosus in females, involvement of the perianal region is uncommon. Therefore, symptoms secondary to perianal erosions and fissures like constipation, stool holding, and rectorrhagia, are rare.

The diagnosis of BXO is established by a combination of clinical and characteristic histologic findings. Histology shows orthokeratosis (thickening of the stratum corneum), a thinned epidermis and a deep band-like lymphocytic infiltrate immediately beneath an altered papillary dermis.

Men with BXO are at increased risk of penile intraepithelial neoplasia, which leads to an increased risk for genital SCC. Longitudinal evaluation is essential in all afflicted patients and all non-healing fissures, ulcers, or nodules should be biopsied to rule out penile intraepithelial neoplasia and SCC.

Treatment of choice for BXO is a potent topical corticosteroid such as clobetasol. The steroid should be applied once daily for three months with subsequent tapering over two weeks. The initial dose alleviates symptoms in the majority of patients and clinical remission is maintained by the tapering application of a corticosteroid. Complete resolution can be seen in some, but any scarring is irreversible. For patients with phimosis, circumcision may be required.

Christopher Chu, BS, is a medical student at Baylor College of Medicine.
Adam Rees, MD­, a graduate of the David Geffen School of Medicine at UCLA, practices dermatology in Los Angeles.