The distinguishing features of ulcers of various etiologies are given in Table 21-1 (Figs. 21-1, 21-2 and 21-3). Additionally, fixed drug eruptions can affect the genitalia, causing intensely painful bullous lesions that may become necrotic. Some patients so afflicted have been mislabeled as having herpes simplex. As always, a complete drug history is warranted (Goldman, 2000).

The mucous membrane of the urethra may be involved in systemic diseases that cause mucosal ulcerations, such as Behçet disease, pemphigus, and Stevens-Johnson syndrome.

Nonulcerating dermatologic diseases that characteristically involve the penis include psoriasis, scabies, and lichen planus.

Psoriasis is the most common inflammatory condition affecting the male genitalia. The patient may have no history of psoriasis or lesions elsewhere and the well-defined erythematous plaques lack the characteristic psoriatic scale (Goldman, 2000).

Contact dermatitis may result from topical agents applied to other areas and transferred to the genitalia from the hands. Obtain a complete history of the use of such preparations. Poison ivy and other forms of Rhus dermatitis are also transferred in this way.

In secondary lues, a papulosquamous eruption typically involves the penis, palms (Fig. 21-4), and soles. This skin lesion is teeming with spirochetes and is highly infectious.

Reiter syndrome is frequently accompanied by circinate balanitis, a painless eruption on the glans. These begin as small blebs that coalesce into a large circular ring about the size of a dime.

Condylomata lata (See Fig. 22-5) are flat growths about the genitalia or anus seen during the secondary stage of syphilis. Condylomata acuminata (venereal warts), which occur in the same locations (See Fig. 22-4), have villous projections, and as these are caused by a virus, they are infectious.

Herpes simplex can initially appear as small grouped vesicles on an erythematous base, which then open and resolve as ulcers. These are highly infectious.

Malignant melanomas occur on the male genitalia, most commonly on the glans or urethra, but are very rare, much rarer than on the vulva (Ahmed, 1997).

Cancer of the penis can be either nodular or ulcerating. While it is rare, morbidity and mortality are relatively high because of delays in diagnosis occasioned by embarrassment, denial, or lack of awareness.

Record whether the patient is circumcised. If not, be sure to retract the foreskin completely and inspect the complete coronal sulcus and glans.

In the event that urine cultures for mycobacteria are done to look for extrapulmonary dissemination of tuberculosis, be aware that laboratories unable to distinguish species could mistake Mycobacterium smegmatis, a contaminant present in the smegma of uncircumcised men, for Mycobacterium tuberculosis.

Penile cancer hardly ever occurs in circumcised men. (Cancer of the cervix is also less common in the wives of circumcised men.)

Peyronie disease is also known as plastic induration of the penis. The patient may complain of curvature of the penis during erection, toward the side of the plaque. Feel for plaques, which are occasionally tender, in the corpora cavernosa laterally or in the intercorporeal septum dorsally. The condition is more common in men who have used penile self-injections to treat impotence.

Priapism is a prolonged, usually painful erection of the corpora cavernosa, initially unaccompanied by sexual desire. The glans penis is usually not engorged. It may signify a neurologic lesion from the cerebrum to the nervi erigentes; a local mechanical cause, such as thrombosis, hemorrhage, neoplasm, or inflammation of the penis; or a thrombotic diathesis due to a hematologic condition such as leukemia or sickle cell anemia (hemoglobin S-S), or even sickle trait (hemoglobin S-A). (Hemoglobin S undergoes sickling when the partial pressure of oxygen in the blood decreases [PO₂]. Persons with hemoglobin S-A usually have PO₂ levels sufficient to prevent sickling—except when they travel by air.) Additional causes of priapism include Fabry disease, amyloidosis, malaria, black widow spider bite, and recent infection with Mycoplasma pneumoniae.

Priapism can also be seen following self-injection of vasoactive agents, as well as use of some oral agents. Up to 21% of cases of priapism are associated with alcohol abuse or drug therapy (Thomas et al., 2003). Take a careful drug history, including the use of illegal agents. Drugs associated with this condition include many psychotropic medications (including chlorpromazine, clozapine, bupropion, trazodone, fluoxetine, sertraline, lithium, mesoridazine, perphenazine, and hydroxyzine), hydralazine, metoclopramide, prazosin, tamoxifen, testosterone, calcium-channel blockers, anticoagulants, cocaine, marijuana, and 3,4-methylenedioxymethamphetamine (MDMA or “ecstasy”). Priapism has also been reported with infusion of a 20% fat emulsion in the course of total parenteral nutrition.

Most men have delayed presentation for many hours because of embarrassment. Delay increases the likelihood of complications such as impotence. Priapism is an emergency requiring immediate treatment.

In hypospadias, the urethra opens on the ventral surface of the penis, from just inside the meatus all the way down the shaft to the penoscrotal junction. This may occur as an isolated anomaly (in 1 of 700 newborn boys). In about 15% of cases, there is some pathogenetic mechanism identified, such as in Klinefelter syndrome (karyotype XXY), other chromosomal abnormalities, maternal ingestion of estrogens or progestogens, or virilizing congenital adrenal hyperplasia in a genetic female (Williams, 1974). Hypospadias may accompany nondescent of the testicle. An asymmetric “hooded” foreskin is often seen with hypospadias.

In epispadias, the urethra opens dorsally.

A thick, purulent-appearing discharge is likely to be a sign of gonorrhea. A slight, whitish discharge is more likely to be due to one of the causes of “nonspecific” (nongonococcal) urethritis
such as Chlamydia, Ureaplasma, or even a presumably noninfectious condition such as Reiter syndrome. Place a drop of the discharge on a slide, allow it to air dry, and prepare a Gram stain to look for leukocytes and gonococci (see Chapter 28).

Sexually transmitted diseases (STDs) may be present even in the absence of symptoms and may only come to the patient’s attention because of a diagnosis made in a partner (see Chapter 22). Men attending an STD clinic were found to have a 17% prevalence of Trichomonas, 19.6% of chlamydia, and 17.7% of gonorrhea. In men with nongonococcal urethritis, 19% were infected with Trichomonas (Schwebke and Hook, 2003).

The physical examination of the penis is seldom helpful in evaluating one of the major causes of morbidity in men, sexual impotence (erectile dysfunction [ED]), unless it is a result of an end-organ problem such as Peyronie disease, phimosis, microphallus, or chordee (Nelson, 1987).

One special maneuver, the postage-stamp test (see Chapter 3), is useful for distinguishing impotence of a central (psychogenic) origin from that secondary to a problem in the neurovascular axis (endocrine, vascular, peripheral neuropathy, etc.). Vascular impotence may be evaluated by measuring the penile-brachial blood pressure gradient (see Chapter 18) but requires Doppler equipment to make the penile artery pressure determination.

See Chapter 3 for a discussion of the history and differential diagnosis in ED.