Guys are familiar with the itchy penis formula, which is basically this: The intensity of an itch in the crotch increases in direct proportion to the severity of the situation in which a guy finds himself. Even with a healthy penis, there's going to be an occasional need for some light "social scratching," which can be handled with relative ease and discretion. But when pubic lice enter the picture, a guy is going to have a hard time keeping his hands off his crotch; more importantly, he's going to need to refrain from sexual activity until his personal pubic lice infestation can be brought under control. Taking care of them, then, is necessary for penis health.

Are they just head lice?

Most people remember head lice scares from their school days; the threat of those pesky nits made a person think twice before he borrowed that awesome baseball cap that his best friend wore all the time. But even though head lice and pubic lice are similar, they're not the same thing.

Nicknamed crabs because of their physical resemblance to those sea creatures, pubic lice are very small; adults rarely break 2 millimeters in length. Their coloring can vary, but they're usually a yellowish gray or red. Because of their small size, though, it's hard to see them, let alone figure out their color.

Are they dangerous?

Pubic lice aren't really dangerous; unlike body lice, they don't transmit disease. But they do cause a guy to itch like mad, and scratching that itch can bring about irritation, inflammation and sores.

Itchiness is the main symptom associated with crabs, but sometimes there are other signs. Tiny dots of blood or black powder may appear on the skin or underwear. Pubic lice bites sometimes leave little bluish dots.

Are they shared?

Crabs are almost always spread by sexual contact. It is possible to get them through other means, such as from bed sheets or towels or from wearing the clothing (usually the underwear) of a person with crabs. Most of the time, however, they come from skin-to-skin contact.

Using a condom, while always recommended, does not provide much protection against pubic lice, and even a guy who practices exemplary personal hygiene can catch them if he beds a partner who has an infestation.

Often, a guy doesn't know he has crabs right away; typically, he starts feeling the need to scratch a few days after his crotch has become infested.

What to do about them?

The first thing to do when a guy suspects pubic lice is to confirm his suspicion by seeing a doctor. The physician will determine the appropriate treatment to use, which may include over-the-counter or prescription treatments, or a combination of both.

Often, doctors prescribe the use of a special shampoo that contains permethrin, which is generally very effective. When using this, or an over-the-counter variation, it is generally recommended that the shampoo be rubbed thoroughly into the infected area and then left alone for several minutes to allow the medication to thoroughly seep in.

After rinsing, the man then needs to take a comb and comb through the hair in search of any lice eggs. Vinegar is frequently used to loosen the eggs from the hairs to which they cling. In some cases, the doctor may then recommend applying the shampoo again and possibly repeating the entire process.

Some men also prefer to shave the crotch in order to help remove the eggs and to make it easier to spot lice.

A thorough cleaning of the bed sheets, pillow cases, blankets and covers is also necessary; they will need to be washed in hot water with an appropriate detergent. Items which cannot be washed may require application of a spray that helps to kill lice; these are usually over-the-counter brands rather than prescriptions.

Itchiness (and the soreness which can accompany excessive scratching) can be treated with the application of a first-rate penis health crème (health professionals recommend Man1 Man Oil) that includes reliable moisturizing ingredients. Especially helpful is a crème that includes both a high-end emollient (such as Shea butter) and a natural hydrator like vitamin E. These ingredients are helpful is maintaining a healthy penis in general, even after lice have been banished.