Sexually Transmitted Diseases (STDs In Women) (cont.)
Ectoparasitic Infections
What are ectoparasitic infections?
Ectoparasitic
infections are infections that are caused by tiny parasitic bugs, such as
lice or mites. They are transmitted by close physical contact, including sexual
contact. The parasites affect the skin or hair and cause itching.
Pubic lice (pediculosis pubis)
Pediculosis pubis
is an infection of the genital area caused by the crab louse (Phthirus pubis).
The lice (commonly called crabs) are small bugs that are visible to the naked eye without the aid of a
magnifying glass or microscope. The lice live on pubic hair (or any other hair)
and are associated with itching.
The treatment for pubic lice is usually with a 1% cream rinse of permethrin that
is applied to the affected area and washed off after 10 minutes. Alternative
treatments include a 1% shampoo of
lindane applied for four minutes before washing off or pyrethrins with
piperonyl butoxide applied for 10 minutes before washing off. None of these
treatments should be used for involvement near the eyes because they can be very
irritating. The patient's bedding and clothing should be machine-washed with hot
water. All sexual partners within the preceding month should be treated for
pubic lice and evaluated for other STDs.
Picture of pubic louse (crab)
Scabies
Scabies is an ectoparasitic infection caused by a
mite (known as Sarcoptes scabiei) that is not visible with the naked eye but
can be seen with a magnifying glass or microscope. The parasites live on the
skin and cause itching over the hands, arms, trunk, legs, and buttocks. The
itching usually starts several weeks after exposure to a person with scabies and
is often associated with small bumps over the area of itching. The itching from
scabies is usually worse at night.
The standard treatment for scabies is a 5% cream of
permethrin (Elimite), which is applied to the entire body from the neck down and then
washed off after 8 to 14 hours. Treatment is repeated in one week. An alternative
treatment is 1 ounce of a 1% lotion or 30 grams of cream of lindane, applied
from the neck down and washed off after approximately eight hours. Unfortunately,
itching may persist for up to two months after successful therapy. Since lindane
can cause seizures when it is absorbed through the skin, it should not be used
if skin is significantly irritated or wet, such as with extensive skin disease,
rash, or after a bath. As an additional precaution, lindane should not be used
in pregnant or nursing
women or children younger than two years old.
Ivermectin (Stromectol) is a drug taken by mouth that has also been successfully used to treat scabies. The CDC recommends taking this drug at a dosage of 200 micrograms per kilogram body weight as a single dose, followed by a repeat dose
two weeks later. While a patient my find that taking a drug by mouth is more convenient than application of the cream, ivermectin has a greater risk of toxic side effects than permethrin and has not been shown to be superior to permethrin in eradicating scabies.
As with pubic lice infection, both the bedding and clothing of an infected
individual should be machine-washed in hot water. Finally, all sexual and close
personal and household contacts within the month before the infection should be
examined and treated if infection is found.
Next: Acquired Immunodeficiency Syndrome (AIDS) »
- amoxicillin, Amoxil, Dispermox, Trimox - Learn more about amoxicillin, including a description, generic and brand names, drug class and mechanism, preparations, storage, reasons for prescription, dosing, effect on pregnancy and nursing mothers, and common side effects.
- Pap Smear - Read about Pap smear, a test to screen for cervical cancer, and precancerous changes in the cervix. Risk factors for abnormal Pap include HPV, smoking medicaitons, and a weakened immune system.
- Scabies - Get the facts on scabies causes (mites), signs, symptoms and treatment. Learn what scabies looks like, how to get rid of it and whether dogs are scabies carriers.
Latest Medical News
Sexual Health RSS