WBR0111
| Author | [[PageAuthor::William J Gibson (Reviewed by Yazan Daaboul, M.D. and Rim Halaby, M.D. [1])]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Genetics |
| Sub Category | SubCategory::Dermatology, SubCategory::Hematology |
| Prompt | [[Prompt::A 23-year-old woman presents to her primary care physician complaining of small violaceous red lesions on her lips, nose, and fingers (shown below). The patient reports that these lesions have appeared rather suddenly, with many arising over the past year. Further history-taking reveals that since childhood, she has had frequent nosebleeds and severe gastrointestinal distress that is often accompanied by black stools. Laboratory studies reveal the following: pH: 7.41 Which of the following conditions is the most likely diagnosis?
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| Answer A | AnswerA::Henoch-Schonlein purpura |
| Answer A Explanation | [[AnswerAExp::Henoch-Schonlein purpura (HSP) is a small-vessel vasculitis caused by IgA immune complex deposition in blood vessels. The syndrome commonly causes kidney disease, abdominal pain, joint pain, and palpable purpura commonly seen in the lower extremities. HSP is not characterized by recurrent episodes of epistaxis, or telangiectasias of the lips, nose, and fingers.]] |
| Answer B | AnswerB::Von-Willebrand's disease |
| Answer B Explanation | [[AnswerBExp::Von Willebrand’s disease is the most common hereditary coagulation abnormality. It is caused by a deficiency of von Willebrand protein, a multimeric protein required for platelet adhesion. Patients often experience recurrent epistaxis, easy bruising and bleeding gums. Telangiectasias of the lips, fingers and nose are not a hallmark of this disease, nor is gastrointestinal bleeding.]] |
| Answer C | AnswerC::Osler Weber Rendu syndrome |
| Answer C Explanation | [[AnswerCExp::Hereditary hemorrhagic telangiectasia (Osler Weber Rendu Syndrome) is an autosomal dominant disorder characterized by recurrent epistaxis, telangiectasias, and gastrointestinal bleeding.]] |
| Answer D | AnswerD::Factor VIII deficiency |
| Answer D Explanation | [[AnswerDExp::Factor VIII Deficiency is the cause of hemophilia A, an X-linked recessive clotting disorder. Patients with hemophilia suffer severe bleeds. The patients will often have an increased PT, normal PTT, and bleeding time.]] |
| Answer E | AnswerE::Thrombotic thrombocytopenic purpura |
| Answer E Explanation | [[AnswerEExp::Thrombotic thrombocytopenic purpura (TTP) is a rare disorder of the blood-coagulation system, causing extensive microscopic clots to form in the small blood vessels throughout the body. Patients with TTP may have nosebleeds due to consumption of platelets in widespread thrombus formation. However, TTP is often sudden in onset, and does not cause telangiectasias of the lips, nose and fingers.]] |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::The patient in this vignette suffers from Osler-Weber-Rendu syndrome (also known as Hereditary Hemorrhagic Telangiectasia, HHT). Her recurrent epistaxis, characteristic telangiectasia, and anemia due to gastrointestinal bleeding are highly suggestive of HHT. Hereditary hemorrhagic telangiectasia is a genetic disorder that leads to abnormal blood vessel formation in the skin, mucous membranes, and often in organs such as the lungs, liver, and brain. It may lead to nosebleeds, as well as digestive tract bleeding (black stools). Treatment focuses on reducing bleeding from blood vessel lesions, and sometimes surgery or other targeted interventions to remove arteriovenous malformations in organs. Chronic bleeding often requires iron supplements and sometimes blood transfusions. HHT is transmitted in an autosomal dominant fashion, and occurs in one in 5,000 people. Educational Objective: Hereditary hemorrhagic telangiectasia (Osler Weber Rendu syndrome) is characterized by recurrent epistaxis, telangiectasias, and gastrointestinal bleeding. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Bleeding, WBRKeyword::Coagulation, WBRKeyword::Coagulopathy, WBRKeyword::Telangiectasia, WBRKeyword::Genetics, WBRKeyword::Autosomal dominant, WBRKeyword::Dermatology, WBRKeyword::Skin, WBRKeyword::Epistaxis |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
