Update on Genital Lesions
Authors: Ted Rosen
Journal: JAMA (2003)

THE APPEARANCE OF AN EXTERNAL genital lesion may engender considerable anxiety in a patient. From the medical professional perspective, genital lesions pose serious diagnostic and therapeutic challenges. Genital skin can erode or ulcerate, develop dyschromia (hyperpigmentation or hypopigmentation) or erythema, and either thicken or atrophy in discrete or generalized fashions. However, genital lesions may result from many etiologies including sexually transmitted diseases (STDs), non-STD infectious agents, inflammatory cutaneous disorders, multisystem diseases, benign and malignant neoplasms, and exogenous (external) factors (TABLE). With the exception of lichen planus, genital lesions in men and women appear nearly identical. Many lesions are indistinguishable to the casual observer. For example, lichen sclerosus et atrophicus (LSA) and vitiligo may be nearly exact clinical mimics (FIGURE 1); however, the former has premalignant potential while the latter is solely of cosmetic concern. Distinguishing between one genital disorder and other similar entities remains difficult even for the well-trained and experienced physician. Prospective studies performed 20 years apart both noted that the diagnostic accuracy for male genital ulcerations varied by disease from a high of only 80% to a low of 33.3%. Attempting a diagnosis based solely on lesion appearance may well lead to inaccuracy in diagnosing either men or women. One should carefully devise a differential diagnosis based on clinical findings and local probabilities (different disease prevalence in varying geographic regions) and then rely on appropriate testing (serologic studies, bacterial and viral cultures, cytologic results, colposcopic examination, and incisional and excisional biopsies) to help clarify the situation. Genital biopsies are relatively easy to perform, heal well, and offer rapid and reliable diagnostic information in both male and female patients. The astute practitioner should never hesitate to recommend and perform a biopsy when diagnostic doubt exists. When attempting to classify genital lesions, it is always important to look at skin outside the affected area. For example, psoriasis and Reiter syndrome both present with red, variably scaling plaques on the genitalia (FIGURE 2). The diagnosis of psoriasis may be favored if sharply demarcated. Erythematous and scaly areas are also found on the elbows and knees, although Reiter syndrome may be favored if hyperkeratotic and erosive lesions are found on the sole (keratoderma blenorrhagicum). Vitiligo may be strongly favored over LSA if depigmented macules are found over bony prominences or around facial orifices, as well as on genital skin. An extensive physical examination, a detailed history, and review of systems are necessary when evaluating a patient with a genital lesion. Patients with psoriasis often have a strong family history of the disease, as do those with vitiligo. A solitary firm nodular lesion that verifiably developed during a short interval should strongly suggest the possibility of malignancy; an indolent nodule present for decades is more likely to be an incidental epidermal cyst. Genital bite wounds can be confirmed quickly by history. Eliciting the complaints of dysuria (urethritis) or burning in the eyes, tearing, or photophobia (conjunctivitis), and/or aching joints (arthritis) helps suggest the diagnosis of Reiter syndrome in the presence of compatible psoriasiform genital lesions. Similarly, although punchedout genital ulcerations of Behcet syndrome may be mistaken for various STDs (particularly chancroid and herpes), symptoms suggesting uveitis, arthritis, and thrombophlebitis help aid the physician in the proper direction.