About once or twice a month, I see a young male in his late teens or early 20s who come to me to evaluate a bump or lesion on his penis. Interestingly, many of these men have sought evaluation before and STILL don't know what they have.
Here are the most common causes of this symptom:
Have multiple grouped lesions on the penis that are painful? Think about genital herpes as the cause. These lesions can also occur on the buttocks or anal area. The initial outbreak may be associated with fever. Herpes is the most common STD in the U.S. and most genital lesions in men are herpes.
Have a bump that looks like a wart or has a cauliflower appearance? You may have genital warts. Warts are caused by certain strains of human papillomavirus -- different ones than those that cause cervical cancer in women. In most cases, the warts do not cause symptoms, but occasionally they can burn, itch or be tender. They can also produce a discharge. The lesions may be tan, pink or hyperpigmented.
Have a single painless ulcer on the penis? Consider syphilis. The painless ulcer is called a chancre and often associated with large, nontender lymph nodes in the groin. The lesions will go away on their own 3-6 weeks after appearance. (but that doesn't mean the infection is gone!)
Have multiple raised pink pearly lesions on the penis? It might be molluscum contagiosum. Caused by a poxvirus, these lesions are usually painless, but if irritated, they can be painful. They can often be diagnosed by their appearance on examination.
Have multiple painful genital ulcers plus painful enlarged lymph nodes in the groin? Though fairly rare in this country, this may be chancroid.
Have a dark itchy area on the penis? Your doctor may want to look for crabs. Usually the crabs are difficult to see with the naked eye, a magnifying glass may help find them. However, the eggs or nits can be seen on the pubic hair and removed with a fine tooth comb.
Have reddened nodules on the penis that are VERY itchy? Your doctor may examine you and look for signs of scabies.
Occasionally, a man may have abscesses in the groin that are often caused by skin bacteria.
So, let's talk diagnosis. First, get it checked out. Fight the temptation to ignore the bump or ulcer. In some cases, the physician may institute therapy based on your history and the appearance of the lesion(s).
In addition to the history that the clinician will obtain, he or she will likely obtain a swab of the lesion to be examined in the lab. Specific cultures can often identify the cause. Moreover, blood tests can be performed to look for the cause. Genital warts have a distinctive appearance and can often be diagnosed using observation alone.
In all cases, the "bump" is treatable. And early treatment is key to preventing transmission of the disease to a sexual partner if it's sexually transmitted. Also, in some cases, early treatment can prevent serious, life-threatening complications (like in the case of syphilis).