Scabies Medication

What is Scabies?

Scabies is a skin disease characterized by infestation of the mite Sarcoptes scabiei.  The condition is typically acquired by close contact with people who have active infection.  Sometimes it is spread through infested linens and clothing.  Individuals with scabies infection typically have severe itching and rash that involve the webs between the fingers and toes, as well as the belt-line, groin and armpits.  Symptoms are usually worse at night.

Scabies is highly contagious and often transmitted to other family members in the household.  Although not life-threatening, the disease can be cosmetically, physically, and psychologically disturbing.  Due to the importance of this condition, it is critical that patients understand its causes, symptoms, and treatment.  By the end of this article, you will have the answers to these essential questions

  • What causes Scabies?
  • How common is Scabies?
  • What are the symptoms and signs of Scabies?
  • How is Scabies diagnosed?
  • How is Scabies treated?

What causes Scabies?

Scabies is caused by the mite Sarcoptes scabiei – this mite infests the skin in certain areas of the body, resulting in an extremely itchy and red rash.  The mite burrows into the skin, resulting in irritation, and inflammation of the epidermis.  This results in erythema (redness) and pruritus (itching).

Scabies is transmitted via close contact with infected individuals.  Patients and children often transmit the infection to each other.  Some patients may develop scabies due to sexual contact – this is usually seen in young sexually active adults.  Sarcoptes scabiei mites can typically survive off their host for up to 2-3 days.

How common is Scabies?

Scabies is common in the United States and frequently evaluated in the primary care clinic.  Atypical or severe cases of the condition may require referral to an infectious disease or dermatology specialist, especially if first-line measures are unsuccessful.

The prevalence of scabies is increased in crowded conditions– in fact, infestations often occur in institutional settings such as nursing homes.  Rates of scabies infection also increase during winter months, likely because people crowd indoors.

What are the symptoms and signs of Scabies?

Symptoms and signs of scabies often include a severely itchy (pruritic) rash that may be red (erythematous), scaly, and typically involves the following locations:

  • Web-spaces between fingers and toes
  • Groin
  • Belt-line
  • Armpits

Patients often have the characteristic appearance of a mite burrow on detailed inspection of the rash.  This often has a zig-zag appearance as the mite moves side to side to drive farther down the skin horizontally.  Individuals with crusted (Norwegian) scabies – a more aggressive form of the mite – typically develop more severe infestation and symptoms.  Crusted scabies typically affects individuals with immunosuppression such as HIV/AIDS.

How is Scabies diagnosed?

Scabies is a clinical diagnosis based on the patient’s symptoms, history, and physical examination.  An itchy rash with the characteristic appearance and distribution is highly suggestive.  Family member involvement is even more strongly suggestive of the disease.

Occasionally, you doctor may confirm the diagnosis by obtaining skin scrapings or performing a dermoscopic examination.  Negative laboratory studies do not necessarily exclude the diagnosis of scabies.  If you have evidence of crusted (Norwegian) scabies, your doctor may perform tests to exclude immunodeficiency such as HIV/AIDS.

How is Scabies treated?

Scabies is treated with symptom control and prescription medications to eradicate infestation and prevent further transmission of the disease.

Your doctor may recommend the following medications:

  • Nix, Elimite - permethrin 5% cream
  • Stromectol - oral ivermectin

Permethrin cream is applied all over the body from the neck down.  The cream should be removed by showing 8-14 hours after drug administration.  An additional application is typically performed one week later.  Similarly, ivermectin is given as a single dose and is repeated after 1-2 weeks.  Individuals with crusted scabies are typically treated with both oral ivermectin and topical permethrin 5% cream simultaneously.

Close contacts of infected individuals should also receive treatment.  Clothing and linens should also be washed in hot water and dried in a hot dryer.  As an alternative, clothing and linens can be bagged for several days.

Scabies Patient Summary:

  • Scabies is caused by Sarcoptes scabiei, a mite that infests the skin.
  • Patient typically develop a severely itchy (pruritic) rash that may be red (erythematous), scaly, and typically involves the following locations: Web-spaces between the fingers and toes, groin, belt-line, and armpits.
  • The mite burrows into the skin, resulting in irritation and inflammation of the epidermis.
  • Patients often have the characteristic appearance of a mite burrow on detailed inspection of the rash. This often has a zig-zag
  • Scabies is transmitted via close contact with infected individuals. Patients and children often transmit the infection to each other.  It can also be spread via sexual contact.
  • Scabies is a clinical diagnosis based on the patient’s symptoms, history, and physical examination. Family member involvement is even more strongly suggestive of the disease given its transmission via close contact. 
  • Your doctor may confirm the diagnosis by obtaining skin scrapings or performing a dermoscopic examination – skin exam using a special scope.
  • Scabies is treated with symptom control and prescription medications to eradicate infestation and prevent further transmission of the disease.
  • Your doctor may recommend the following medications: Nix, Elimite - permethrin 5% cream, Stromectol - oral ivermectin.
  • Permethrin cream is applied all over the body from the neck down. The cream should be removed by showing 8-14 hours after administration.  An additional application is typically performed one week later to ensure disease eradication. 
  • Ivermectin is given as a single oral dose and is repeated after 1-2 weeks. Crusted scabies is typically treated with both oral ivermectin and topical permethrin 5% cream simultaneously due to its aggressive course.
  • Close contacts of infected individuals should also receive treatment. Clothing and linens should also be washed in hot water and dried in a hot dryer.  As an alternative, clothing and linens can be bagged for several days.

References:

  1. Chosidow O. Clinical practices. Scabies. N Engl J Med 2006; 354:1718.
  2. Fuller LC. Epidemiology of scabies. Curr Opin Infect Dis 2013; 26:123.

 

 

 

Oral Medication for Scabies

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.