WBR0417
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| Author | [[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Yazan Daaboul, M.D.)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Microbiology |
| Sub Category | SubCategory::Dermatology |
| Prompt | [[Prompt::A 10-year-old boy is brought to the physician’s office with complaints of intense itching of both hands. Physical examination is remarkable for multiple lesions of his distal upper extremities with papular eruptions in the inter-digital spaces. Burrows are observed using ink test and special light. The physician suspects a skin infestation caused by a parasite whose image is shown in the image below. What advice should the physician give to this patient to treat his condition?
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| Answer A | AnswerA::Hand wash with water and soap that contains antibiotics is necessary |
| Answer A Explanation | [[AnswerAExp::Scabies is caused by a parasite, not bacteria, so hand wash alone is not sufficient for treatment of scabies.]] |
| Answer B | AnswerB::Replacement of soap with hypoallergic soap is necessary |
| Answer B Explanation | AnswerBExp::Despite a manifestation similar to that of an allergy, scabies is not an allergic condition. Replacement of soap with hypo-allergic soap is not helpful. |
| Answer C | AnswerC::A psychiatric consultation is necessary |
| Answer C Explanation | [[AnswerCExp::Delusional parasitosis (Ekbom’s syndrome) is a form of psychosis where patients believe they are infested with parasites. In patients with Ekbom's syndrome, physical examination would not reveal any skin findings.]] |
| Answer D | AnswerD::Washing beddings, clothes, and furniture is necessary |
| Answer D Explanation | AnswerDExp::Washing personal items, such as clothes, towels, and beddings, is necessary for appropriate eradication of scabies. |
| Answer E | AnswerE::Transparent adhesive tape applied to the anal area is necessary |
| Answer E Explanation | [[AnswerEExp::A scotch tape test is useful for the diagnosis of Enterobius vermicularis (pinworms). Pinworms are nematodes (roundworms) that are transmitted by egg-contaminated foods. Patients infected with pinworms are often treated with bendazoles or pyrantel pamoate.]] |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::Scabies is a skin infestation caused by Sarcoptes scabiei (itch mite). Scabies is a highly contagious disease that is often transmitted by direct skin-to-skin contact. Typically, scabies manifests with generalized intense pruritus that spares the head and the face. Patients often also complain of worsening symptoms at night. Commonly affected areas are the inter-digital regions, elbows, axillae, buttocks, breasts, and genital region. The diagnosis of scabies is clinical and is often confirmed using the burrow ink test (BIT). Ink is applied to the suspected area, which is then cleaned with alcohol. When special light is applied to the area, burrows will demonstrate characteristic zig-zag tunnels. Blade scraping across the lateral skin and examination with light microscopy is also helpful to establish the diagnosis. Topical medications (permethrin, lindane, benzyl benzoate, and crotamiton) and oral ivermectin are used to treat scabies. Because scabies is highly contagious, pharmacological therapy should also be administered to other household members. Washing personal items, such as clothes, towels, and beddings, is necessary for appropriate eradication. Items that cannot be washed should be placed in sealed plastic bags for at least 3-7 days until all the mites die inside. Educational Objective: Scabies is caused by the Sarcoptes scabiei (itch mite) and is a contagious disease that is often transmitted by skin-to-skin contact. In addition to the administration of topical/oral drugs to patients and other household members, washing personal items, such as clothes, towels, and beddings, is necessary for appropriate eradication. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Scabies, WBRKeyword::Parasite, WBRKeyword::Skin, WBRKeyword::Lesions, WBRKeyword::Itching, WBRKeyword::Contagious, WBRKeyword::Pruritus, WBRKeyword::Burrows, WBRKeyword::Advice, WBRKeyword::Itch mite, WBRKeyword::Mite, WBRKeyword::Sarcoptes scabiei, WBRKeyword::Burrow ink test |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
