This study aims to report a case of misdiagnosis and delay in the initiation of treatment of a patient with scabies and to emphasize the importance of dermoscopy and direct examination in improving the diagnostic accuracy of scabies. A 2-year-old boy, seen at a pediatric dermatology ambulatory in May 2022, complaining of pruritus for about 2 months. He had been previously diagnosed with dermatophytosis and atopic dermatitis and had been treated for a month with topical moisturizer and antifungal. On examination, diffuse cutaneous xerosis and confluent erythematous papules on the feet were observed. Upon dermoscopic examination of the region, serpiginous tunneling and the delta glider sign at the end of the tunnel were observed between the lesions, which respectively represent the path taken by Sarcoptes scabiei in the epidermis and its anterior portion. Superficial curettage with scalpel blade was performed exactly where the delta glider sign was found, with deposition of the material on a microscope slide with 10% potassium hydroxide. Then direct examination under the optic microscope, revealed the mite, confirming the diagnosis of scabies. We can say that dermoscopy associated with direct examination is a non-invasive, simple and low-cost diagnostic method that allows an accurate diagnosis of this highly contagious dermatosis, which has the potential to cause epidemic outbreaks, and which is still rather neglected.

Several studies have shown that dermoscopy has high sensitivity in the diagnosis of scabies, up to 91%, and that the skin scraping and direct examination associated with previous dermoscopy guarantees greater accuracy and speed for the diagnosis. This study aims to report a case of misdiagnosis and delay in the initiation of treatment of a patient with scabies; and to emphasize the importance of dermoscopy and direct examination in improving the diagnostic accuracy of scabies. A 2 years old boy, seen at a pediatric dermatology ambulatory in May 2022, complaining of pruritus for about 2 months. He had been previously diagnosed with dermatophytosis and atopic dermatitis and had been treated for a month with topical moisturizer and antifungal. On examination, diffuse cutaneous xerosis and confluent erythematous papules on the feet were observed. Upon dermoscopic examination of the region, serpiginous tunneling and the delta glider sign at the end of the tunnel were observed between the lesions, which respectively represent the path taken by Sarcoptes scabiei in the epidermis and its anterior portion. Superficial curettage with scalpel blade was performed exactly where the delta glider sign was found, with deposition of the material on a microscope slide with 10% potassium hydroxide. Then direct examination under the optic microscope, revealed the mite, confirming the diagnosis of scabies. We can say that dermoscopy associated with direct examination is a non-invasive, simple and low-cost diagnostic method that allows an accurate diagnosis of this highly contagious dermatosis, which has the potential to cause epidemic outbreaks, and which is still rather neglected.

ESDR170 - Misdiagnosis of scabies: How dermoscopy and direct examination can improve scabies diagnosis accuracy

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.