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Lindane Facts: The Truth About Lindane

Understanding Scabies and Lice

The Diagnosis — Scabies, Head Lice and Pubic Lice

Accurate diagnosis of scabies and lice infestations is essential for successful treatment of individuals and containment of outbreaks or epidemics in large population groups. While some patients suffering from these highly-contagious health conditions are easily diagnosed, a considerable number of cases are misdiagnosed. This can lead to mismanagement and also contributes to the development of treatment-resistant forms of scabies and lice, which further compromises effective disease control. Click here to learn why second-line treatments are medically necessary for some patients.

An accurate diagnosis of scabies is not always simple

Scabies is characterized by an even distribution of skin lesions on the left and right sides of the body, in several commonly affected zones.2

Sometimes, the telltale signs of scabies are readily apparent.1 In other instances, scabies can mimic other skin conditions with similar clinical characteristics.2 A high degree of suspicion of scabies, based on a patient’s history and lifestyle, is necessary for an accurate diagnosis of scabies infestation because of the variety of signs and symptoms that may or may not be present.3

Telltale signs of scabies include:

Scabies is associated with a red bumpy rash and intense itching; scratching can lead to sores and secondary bacterial infection5,6

Less specific signs of scabies include:2,3

Microscopic identification of scabies infestation can pose a challenge—even for highly-trained healthcare professionals—but is the only way to make a definitive diagnosis1

Microscopic image of scabies mites.

Making a definitive diagnosis of scabies:

Diagnosing lice infestation can also be challenging

Lice infestations are associated with a range of symptoms or none at all.7 Head lice in particular are often managed in school settings where misdiagnosis is a common problem.8 Moreover, patients may self-medicate with over-the-counter remedies prior to seeing a healthcare provider, which can further obscure diagnosis and proper management.7

Scanning electron micrograph image of head louse and egg or “nit” firmly cemented to hair shaft.

Common signs and symptoms of lice infestation:

Head lice infestation is often misdiagnosed:8

Misdiagnosis of lice infestation leads to improper treatment and may also contribute to increased drug resistance8

Accurate diagnosis of lice infestation requires visualization of crawling lice.

Definitive diagnosis requires visualization of crawling lice:

References:

  1. Karthikeyan K. Treatment of scabies: newer perspectives. Postgrad Med J. 2005;81:7–11.
  2. Orion E, Matz H, Wolf R. Ectoparasitic sexually transmitted diseases: scabies and pediculosis. Clin Dermatol. 2004;22(6):513–519.
  3. Johnston G, Sladden M. Scabies: diagnosis and treatment. British Med J. 2005;331:619–622.
  4. Habif TP. Scabies. In: Clinical Dermatology, 4th edition. New York: Mosby; 2004:497–505.
  5. Walton SF, Holt DC, Currie BJ, et al. Scabies: new future for a neglected disease. Adv Parasitol. 2004;57:309–376.
  6. U.S. Centers for Disease Control and Prevention (CDC). Parasitic Disease Information: Scabies Fact Sheet. 2005. Available at: http://www.cdc.gov/parasites/scabies/epi.html.
  7. Ko CJ, Elston DM. Pediculosis. J Am Acad Dermatol. 2004;50(1):1–12; quiz 13–4.
  8. Hansen RC. Overview: the state of head lice management and control. Am J Manag Care. 2004;10(9 Suppl):S260–S263.
  9. Habif TP. Pediculosis. In: Clinical Dermatology, 4th edition. New York: Mosby; 2004:506–510.