Pediculosis capitis (head lice infestations) occur in all age groups, but especially in elementary school children. In most cases, transmission occurs by head-to-head contact. Pharmacologic treatment is recommended for persons with live lice or eggs (nits) within 1 cm of the scalp. Topical pediculicides should be tried first. Oral therapy is occasionally required for refractory infestations.

Topical ivermectin lotion 0.5% (Sklice, and generics), which has been available by prescription since 2012, is now FDA-approved for sale over the counter (OTC) for treatment of head lice in patients ≥6 months old. Ivermectin is also available by prescription as a 1% cream (Soolantra) approved for topical treatment of inflammatory lesions of rosacea and in oral tablets (Stromectol, and generics) for treatment of various parasitic infections.

This article includes recommendations for management of most sexually transmitted infections (STIs) other than HIV and viral hepatitis. Some of the indications and dosages recommended here have not been approved by the FDA (see Table 1).

The Centers for Disease Control and Prevention (CDC) and the Environmental Protection Agency (EPA) recommend using insect repellents to prevent infections transmitted by mosquitoes and ticks. Insect repellents applied to exposed skin should be used in conjunction with other preventive measures such as wearing pants and long-sleeved shirts and avoiding outdoor activities during peak mosquito-biting times. Mosquitoes can transmit diseasecausing pathogens, including Zika, chikungunya, dengue, West Nile, eastern equine encephalitis, and yellow fever viruses, and the malaria parasite. Ticks can transmit the bacteria that cause Lyme disease, the rickettsia that cause Rocky Mountain spotted fever, and viruses such as Powassan virus. Some insect repellents containing EPA-registered active ingredients are listed in Table 1.

Patients who receive pretravel advice can reduce their risk for many travel-related conditions. Vaccines recommended for travelers are reviewed in a separate issue.

Use of insect repellents is strongly recommended by the Centers for Disease Control and Prevention (CDC) and the Environmental Protection Agency (EPA) to prevent infections transmitted by mosquitoes and ticks. Insect repellents applied to exposed skin should be used in conjunction with other preventive measures such as wearing pants and long-sleeved shirts, and avoiding outdoor activities during peak mosquito-biting times. Mosquitoes can transmit Zika, chikungunya, dengue, West Nile, eastern equine encephalitis, and yellow fever viruses, as well as malaria. Ticks can transmit Lyme disease, rickettsial diseases such as Rocky Mountain spotted fever, and viruses such as Powassan virus.

The text and tables that follow include recommendations for management of sexually transmitted infections (STIs) other than HIV and viral hepatitis. Some of the indications and dosages recommended here have not been approved by the FDA.

Use of insect repellents is strongly recommended by the CDC and the EPA to prevent Zika virus infection and other mosquito- and tickborne diseases. Mosquitoes can transmit chikungunya, dengue, West Nile, and yellow fever viruses, and malaria. Ticks can transmit Lyme disease and rickettsial diseases such as Rocky Mountain spotted fever.

Patients planning to travel to other countries often ask for information about prevention of diarrhea, malaria, and other travel-related conditions. Vaccines recommended for travelers based on their destination, length of stay, and planned activities were reviewed in a previous issue.

Many infections can be transmitted during sexual contact. The text and tables that follow include recommendations for management of sexually transmitted infections (STIs) other than HIV, viral hepatitis, and enteric infections. Some of the indications and dosages recommended here have not been approved by the FDA.

The pathogenesis of acne is multifactorial: follicular hyperkeratinization, bacteria, sebum production, androgens, and inflammation all play a role. The gram-positive microaerophilic bacteria Propionibacterium acnes promote development of acne lesions by secreting chemotactic factors that attract leukocytes to the follicle, causing inflammation.

The CDC has received a record number of reports of West Nile virus infection this year – 1993 as of September 4, including 87 deaths – and strongly recommends use of insect repellents to prevent transmission of West Nile virus and other mosquito-borne diseases. Insect repellents have been used on the skin for many years to prevent mosquito bites, which can transmit malaria, dengue, and various types of encephalitis. In recent years, insect repellents have also been recommended as protection against ticks, which transmit Lyme disease.

The FDA has approved the antiparasitic drug ivermectin in a 0.5% lotion (Sklice – Sanofi Pasteur) as a single-use topical treatment for head lice in patients ≥6 months old. Oral ivermectin (Stromectol – Merck) is effective for treatment of head lice resistant to other therapies, but it has not been approved by the FDA for this indication.

Patients planning to travel to other countries often ask for information about appropriate vaccines and prevention of diarrhea and malaria. More detailed advice for travelers is available from the Centers for Disease Control and Prevention (CDC) at www.cdc.gov/travel. Guidelines are also available from the Infectious Diseases Society of America (IDSA).

The FDA has approved spinosad 0.9% suspension (Natroba – ParaPro) for topical treatment of head lice infestation in patients ≥4 years old. It is available only by prescription.

Most cases of Lyme disease in the US occur between May and September in the Northeastern, Mid-Atlantic and North Central states.

Many infections can be transmitted during sexual contact. The text and tables that follow are limited to management of sexually transmitted infections (STIs) other than HIV, viral hepatitis and enteric infections. The drugs of choice, their dosages and alternatives are listed in a table that begins on page 54. A table listing the adverse effects of some of these antimicrobials begins on page 58.

The FDA has approved benzyl alcohol lotion, 5% (Ulesfia Lotion - Sciele) for treatment of head lice in patients ≥6 months old. The active ingredient is 5% benzyl alcohol; the vehicle is 5% mineral oil.

The pathogenesis of acne is multifactorial: follicular hyperkeratinization, bacteria, sebum production, androgens and inflammation all play a role. The gram-positive microaerophilic bacteria Propionibacterium acnes promote development of acne lesions by secreting chemotactic factors that attract leukocytes to the follicle, causing inflammation.

Many infections can be transmitted during sexual contact. The text and tables that follow are limited to management of sexually transmitted infections (STIs) other than HIV, viral hepatitis and enteric infections. Guidelines are available from the US Centers for Disease Control and Prevention (CDC) with detailed recommendations for treatment of these diseases.

Most cases of Lyme disease in North America occur between May and September. In 2005, 12 states (CT, DE, ME, MD, MA, MI, NH, NJ, NY, PA, VA, WI) reported about 95% of all the Lyme disease in the US, but some cases occurred in all states except AR, CO, HI, MS, MT and OK. New guidelines for treatment of Lyme disease have been published.

Patients planning to travel to other countries often ask physicians for information about immunizations and prevention of diarrhea and malaria. More detailed advice for travelers is available from the Centers for Disease Control and Prevention at 877-FYI-TRIP (877-394-8747) or www.cdc.gov/travel.

Head lice occur in all age groups, but especially in elementary school children during the winter months. Infestations are becoming more difficult to treat because of increasing resistance to the chemical pediculicides commonly used, particularly those that are available over-the-counter (OTC).

The pathogenesis of acne is multifactorial: follicular hyperkeratinization, Propionibacterium acnes bacteria, sebum production, androgens and inflammation have all been implicated. P. acnes, a gram-positive microaerophilic bacterium, plays an important role in the development of acne lesions by secreting chemotactic factors that attract leukocytes to the follicle, causing inflammation.

Lyme disease in North America is caused by the spirochete Borrelia burgdorferi, which is transmitted to humans by Ixodes scapularis or pacificus ticks. These ticks may also carry other pathogens; coinfection with Babesia microti or Anaplasma phagocytophilum (formerly Ehrlichia) has been reported.1 In 2001 and 2002, 12 states (CT, DE, ME, MD, MA, MI, NH, NJ, NY, PA, RI, WI) reported about 95% of all the Lyme disease in the US, but cases occurred in all states except HI, MT and OK. Most Lyme disease in North America occurs between May and September.

Many infections can be transmitted during sexual contact. The text and tables that follow are limited to management of sexually transmitted infections (STIs) other than HIV, viral hepatitis and enteric infections. Guidelines are available from the US Centers for Disease Control and Prevention (CDC) with detailed recommendations for treatment of these diseases (MMWR Recomm Rep 2002; 51, RR-6:1). New guidelines are expected soon.

Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites. The table below lists first-choice and alternative drugs for most parasitic infections. The brand names and manufacturers of the drugs are listed in this article.

Insect repellents have been used on the skin for many years, primarily to prevent mosquito bites, which transmit malaria, West Nile virus infection, and various types of encephalitis. With increased concern about Lyme disease in recent years, skin and clothing repellents are now also recommended for protection against ticks. This review describes the effectiveness of the most widely used repellents DEET and permethrin , as well as some alternatives, and a new product called picaridin that may be available soon. The safety of these products is also discussed. The review concludes with an overall assessment of safety and efficacy and a recommendation on how to achieve the best protection.

Patients planning to travel to other countries often ask physicians for advice about immunizations and prevention of diarrhea and malaria. More detailed advice for travelers is available from the CDC at 877-FYI-TRIP (877-394-8747) or www.cdc.gov/travel.

Superseded--purchase updated Parasitic Infections article
Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites.

Note: Drugs for Parasitic Infections, revised and updated, is now available to both subscribers and nonsubscribers on our web site. This article, a bi-annual feature of The Medical Letter for many years, will not be published as a printed issue in 2002, but is included in the 16th edition of The Medical Letter Handbook of Antimicrobial Therapy. The handbook is now available and can be ordered by calling customer service at 1-800-211-2769.

Many infections can be transmitted during sexual contact. The text and tables [in this article] are limited to treatment of non-HIV infections associated primarily with sexual transmission.

0.5% malathion in 78% isopropanol was recently approved by the FDA for treatment of head lice.

(Superseded by the 2013 version. Click here to purchase.)
Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites. The table lists first-choice and alternative drugs for most parasitic infections.

Several readers have asked the Medical Letter to review the treatment of head lice, which apparently have become increasingly resistant to recommended drugs (KY Mumcuoglu, American Entomologist, Fall 1996, page 175). Assays for drug resistance of head lice have not been standardized, however, and poor technique, such as not using a louse comb after treatment to remove lice and nits (eggs), may be responsible for some treatment failures. The last Medical Letter article on treatment of parasitic infections (vol. 37, page 99, November 10, 1995) recommended 1% permethrin (Nix) or 0.5% malathion (Prioderm; Ovide) as the drug of choice for treatment of head lice and pyrethrins with piperonyl butoxide (Rid, and others) as an alternative.

Patients planning to travel to other countries often ask physicians for advice about immunizations and prevention of diarrhea and malaria. More detailed advice for travelers is available from the CDC at 877-FYI-TRIP (877-394-8747) or www.cdc.gov/travel.

Patients planning to travel to other countries often ask physicians for advice about immunizations and prevention of diarrhea and malaria. Legal requirements for entry and epidemiological conditions in different countries vary from time to time, often unpredictably, but some reasonable recommendations can be made. More detailed information is available in Health Information for International Travel, published annually by the Centers for Disease Control (CDC), which can be obtained from the Superintendent of Documents, US Government Printing Office, Washington, DC 20402. Up-to-date automated information is available by telephone from the CDC (404-332-4559).

Ovide Lotion (GenDerm), 0.5% malathion in 78% alcohol, was recently approved by the US Food and Drug Administration for treatment of head lice; it is available only by prescription. A previous formulation of malathion (Prioderm Lotion - Medical Letter, 25:30, 1986) was commercially unsuccessful in the USA and was withdrawn.

Insect repellents have been used on the skin for many years, primarily to prevent mosquito bites. With recent increased concern about Lyme disease, skin and clothing repellents are now also recommended for protection against ticks.