Diagnosing Scabies

Overview

Scabies is a highly contagious skin condition caused by tiny mites called Sarcoptes scabiei. These mites burrow into the skin and lay eggs, leading to intense itching, especially at night. To diagnose scabies, healthcare providers use a combination of clinical examination and laboratory tests, including:

• History and Questionnaire: The healthcare provider may ask about symptoms, duration of symptoms including presence of itching, and other factors such as living conditions or physical contact with others who may have scabies.
• Clinical Examination: A doctor will visually inspect the rashes and affected areas of the skin to check for signs of mites or skin irritation.
• Skin Scraping: A small sample of the skin may be taken using a scalpel or a special tool called a curette. This sample is then examined under a microscope to look for the presence of mites, eggs, or fecal pellets. Skin scraping is a common diagnostic method for scabies.
• Tape Test: Another method is the tape test, where clear adhesive tape is applied to the affected area and then gently removed. The tape is then examined under a microscope to check for mites or eggs that may have been picked up.
• Dermoscopy: Dermoscopy involves using a special device called a dermatoscope to examine the skin more closely. It allows for detailed visualization of scabies mites in vivo and can confirm the diagnosis of scabies.
• Blood Tests: Diagnosis often is made based upon the physical examination and tests that identify the presence of mites. In some cases, blood tests may be used to confirm diagnosis. These may include:
  • Serological Testing: Serological testing involves detecting specific antibodies in the blood that are associated with scabies infection. While these tests show promise for future use, they are still being studied to improve their accuracy and reliability.
  • Molecular Identification: PCR amplification is a molecular identification method that is being research to accurately and rapidly diagnose scabies.

These examinations and tests help confirm a diagnosis of scabies by identifying the presence of mites, eggs, or other indicators of scabies infection. Additional examinations, tests, or procedures may be done to determine the severity of scabies. These include:

• Assessment of Skin Lesions: Doctors may assess the number and appearance of skin lesions (such as papules, excoriation, pustules) to determine the severity of infestation.
• Presence of Crusts: The presence or absence of crusts on the skin can also indicate the severity of scabies.
• Evaluation for Secondary Bacterial Infection: Doctors may look for signs of secondary bacterial infection such as pustules or yellowish crusts.

Various specialists may be involved in diagnosing scabies, including:

• Dermatologists: These doctors specialize in diagnosing and treating skin conditions, including scabies.
• Pediatricians and General Practitioners (GPs): These doctors often encounter scabies and can diagnose and manage cases of scabies.
• Infectious Disease Specialists: In cases where there are complications or severe infestations, infectious disease specialists may be consulted.

It's important to consult with a healthcare professional for an accurate diagnosis so that appropriate treatment can be started.