Antiparasitic agents are prescribed to treat a variety of skin-related conditions, including:

• Lice. Head lice (pediculus capitis) are bloodsucking, wingless insects approximately the size of a sesame seed. They are the most common form of lice infestation in the United States, and they are shaped like a small capsule that resembles dandruff. Head lice are spread through personal contact and by shared combs, brushes, hats and other personal items. Pubic lice (Pthirus pubis) are usually transmitted by intimate or sexual contact. Pubic lice bear a resemblance to the common crab, with infestations sometimes referred to as a case of “crabs.” They are most often located around the genitals, but may spread to other areas (e.g., abdomen, armpits). Itching (pruritus) is the most common symptom of lice infestation. Lice treatments are typically repeated after 7 to 10 days to kill lice that hatch after the initial treatment.
  
  
• Scabies. An infectious skin disease that results from a mite infestation. Scabies occurs throughout the world and is spread by personal contact and shared use of clothing and bedding. The mites burrow into the skin and cause an itchy rash. They then deposit eggs under the skin, which appear as a burrow that resembles a pencil mark. Eggs mature in 21 days. Scabies can occur with small blisters, and is commonly found on the genitals.
  
  
• “Creeping eruption.” An often serpiginous (winding) skin rash that results when a person becomes infected with dog or cat hookworm (larva migrans) through contact with the animals’ feces, and the larvae begin to “creep” beneath the skin. Symptoms usually appear on the feet, buttocks or back. Creeping eruption tends to occur in warm climates when people are exposed to the larvae found in sands and soils. In the United States, it is most common in the Southeastern states.