PACKRAT 1 exam 2023 with 100% correct answers

A patient presents with eye pain and blurred vision. Snellen testing reveals vision of 20/200 in the affected eye and 20/20 in the unaffected eye. Fluorescein staining reveals the presence of a dendritic ulcer. Which of the following is the most likely diagnosis? A. Viral keratitis B. Fungal corneal ulcer C. Acanthamoeba keratitis D. Bacterial corneal ulcer (c) A. Herpes Simplex virus is a common cause of dendritic ulceration noted on fluorescein staining. (u) B. Fungal corneal ulcers have an indolent course with intraocular infection being common but fluorescein staining is negative for a dendritic pattern. (u) C. Acanthamoeba keratitis has a waxing and waning course over several months and has no fluorescein staining in a dendritic pattern. (u) D. Bacterial corneal ulcers can progress aggressively resulting in corneal perforation. Fluorescein staining does not occur in a dendritic pattern. A 6 year-old male presents with hemarthrosis of the left knee. Coagulation studies reveal the following results: PT 12.5 seconds (normal range 12-14 seconds), INR 1.0, aPTT 58 seconds (normal range 18-28 seconds), platelet count 430,000/microliter (normal range 150,000-450,000/microliter), and bleeding time 4 minutes (normal range 2-12 minutes). Which of the following is the best treatment option for this patient? A. Desmopressin acetate B. Corticosteroids C. Vitamin K D. Cryoprecipitate (u) A. Desmopressin acetate is indicated in von Willebrand's disease, which presents with a prolonged bleeding time. (u) B. Corticosteroids are indicated in immune-mediated thrombocytopenia. (u) C. Vitamin K deficiency will prolong the PT greater than the aPTT. Vitamin K supplement is not indicated in this patient. (c) D.Hemophilia A presents with a prolonged aPTT and normal platelet count and function. Hemophilia A is treated with factor VIII concentrate or cryoprecipitate. An HIV positive patient presents with worsening dementia, fever, headache, and right hemiparesis. MRI of the brain reveals six lesions throughout the brain that show ring enhancement and surrounding edema. Which of the following is the treatment of choice? A. Sulfadiazine and pyrimethamine B. Trimethoprim-sulfamethoxazole C. Radiation therapy D. Ventricular shunt placement (c) A. Toxoplasmosis is commonly noted in HIV positive patients and presents with multiple ring-enhancing lesions. Treatment of choice for possible toxoplasmosis is sulfadiazine and pyrimethamine. (u) B. Trimethoprim-sulfamethoxazole is used for prophylaxis of toxoplasmosis, but not for treatment of acute infection. (u) C. Radiation therapy is indicated in CNS lymphoma, which typically presents with a single lesion. (u) D. Shunt placement is not indicated in patients with toxoplasmosis.