Antiparasitic agents are medications used to treat conditions that occur when parasites infest the body. Parasites survive by living on and feeding off a host. There are many different types of antiparasitic agents, including several that are used to treat skin conditions, such as scabies, head lice, pubic lice and “creeping eruption.”

These medications work by either paralyzing parasites or by killing them outright. They are available in the form of pills, creams, lotions and shampoos. Some of these drugs are available in over-the-counter formulations, whereas others can only be obtained through a physician’s prescription.

Many of these drugs require patients to cover their entire bodies with a lotion or cream, starting with the scalp (as long as it is not already inflamed) and continuing from the neck to the toes, while excluding the face. Patients should pay particular attention to ensuring that the medicine covers skin folds, creases and the areas between the fingers and toes. The medication must also be applied under the fingernails. Repeat applications may be necessary if new lesions occur after the treatment has been performed.

Patients should be aware that the itchiness associated with scabies, lice and creeping eruption generally continues for anywhere from a couple of days to as long as several weeks after antiparasitic medication is first used. This is normal and does not indicate that the treatment is unsuccessful.