A stroll down the pharmacy aisle is proof enough that genital symptoms plague our population. The sheer number of products such as cleaning wipes, douches, anti-itch sprays, and antifungal preparations is overwhelming. Many patients will go to great lengths to solve genital symptoms on their own, whether motivated by embarrassment, lack of access to medical care, or uncertainty as to which medical professional is best suited to treat the problem. Indeed, many clinicians also share this uncertainty. On the other hand, patients can be too certain of a diagnosis, for example ascribing any vulvar itching, burning, or discomfort to a yeast infection. Diseases are often diagnosed via telephone, and medications (especially antifungal treatments) are often prescribed without a physical examination.
Knowledge of normal genital anatomy, as well as normal variants of the male and female genitalia, must form the basis for any approach to diagnosing genital disease.
Keratinized, hair-bearing skin is present on the scrotum and penile shaft in males and on the labia majora in females.
Modified mucous membranes with a minimal keratin layer are present on the glans in males and medial labia majora and labia minora in females.
True mucous membranes with no keratin layer are present on the urethral meatus in males and the vagina and introitus beginning at Hart's line in females.
In males, surgical removal of the prepuce (foreskin) decreases the incidence of penile cancers, genital warts, psoriasis, erosive lichen planus, lichen sclerosus, and several sexually transmitted infections including herpes simplex and human immunodeficiency virus (HIV).1
Knowledge of anatomic boundaries, and the typical locations of certain conditions, may aid the clinician in distinguishing diseases with similar morphologic features. For example, involvement of the mucous membranes favors lichen planus over lichen sclerosus. Involvement of the intertriginous regions favors a candida infection, whereas sparing of the creases may implicate a contact dermatitis. A well-defined, scaly red plaque involving the scrotum may suggest lichen simplex chronicus, while tinea cruris, which is also red, scaly, and itchy, tends to spare the scrotum and favor the skin folds.
Normal variations of the genitalia commonly lead patients to seek medical attention, often in the setting of new-onset symptoms, or at the initiation of sexual activity. In the latter situation, these variants may be mistaken for sexually transmitted infections. This is often the case with pearly penile papules and vulvar papillae, which are present in more than one-third of uncircumcised males and premenopausal women, respectively; both are frequently misdiagnosed as genital warts.2 Unlike warts, these papules are usually symmetric, exhibit domed rather than filiform tips, and have a discrete base. Prominent sebaceous glands (Fordyce spots) are also commonly mistaken for genital warts. These 1 to 2 mm yellowish papules occur on the modified mucous membranes, including the labia minora and distal shaft of the penis, and may coalesce to ...