Case-based MCQ

A 3-week-old African American boy is brought to the Emergency Department because of a generalized seizure 2 hours ago. The infant is highly irritable with incessant high pitched crying. The infant's weight is 2.5 kg (250 gm below birth weight), blood pressure is 70 /40 mm Hg, pulse is 145/min and respirations are 50/min. Laboratory results show:   Blood glucose 6.6 mmol/L   Urea nitrogen 18 mmol/L   Serum sodium 170 mmol/L   Serum calcium 2.1 mmol/L   Serum magnesium 0.6mmol/L   Which of the following is the most likely cause of this infant’s seizure? A. A Hypocalcemia B. Hypoglycemia C. Hypomagnesemia D. Intracranial hemorrhage E. Meningitis

The correct answer is B. Rh-negative pregnant women who are carrying an Rh-positive fetus are at risk for Rh isoimmunization. Therefore, if the patient is Rh-positive, or both the patient and her partner are Rh-negative, there is no risk. In Rh isoimmunization, transplacental hemorrhage causes the Rh-negative mother to produce antibodies to the Rh-antigen of the fetus. The antibodies then destroy fetal red blood cells. The first exposure usually does not produce Rh isoimmunization. It is generally the second exposure that causes hemolytic disease in the fetus. Severe exposure can cause anemia, hydrops fetalis, and neonatal kernicterus. ⚠ Choice A is not correct: If both the patient and the father are Rh-negative, there is no risk of Rh isoimmunization. ⚠ Choice C and D are not correct: Rh isoimmunization occurs in Rh-negative, not Rh-positive, women. Summarized Points: To prevent Rh isoimmunization, unless the father is also Rh-negative, all Rh-negative pregnant women should receive the RhoGAM injection at 28-weeks gestation, within 72 hours of delivery if the neonate is Rh-positive, if they experience vaginal bleeding or abdominal trauma during pregnancy, have any form of miscarriage, have an invasive procedure such as CVS or amniocentesis, have an external cephalic version, or experience an ectopic pregnancy.

A 25-year-old woman presents to the emergency department with a chief complaint of vaginal bleeding. She states that she is approximately 18-weeks pregnant and has not received any prenatal care. Laboratory studies, including ABO/Rh testing, are ordered and pending at this time. Which of the following patients should receive the RhoGAM injection to prevent Rh isoimmunization? A. An Rh-negative patient whose partner is Rh-negative B. An Rh-negative patient whose partner's blood type is unknown C. An Rh-positive patient whose partner is Rh-positive D. An Rh-positive patient whose partner's blood type is unknown

The correct answer is C. This patient's presentation is suspicious for child abuse and neglect, considering the developmental delay and disheveled/dirty appearance of the child. Injuries that seem unlikely to be explained by the proposed history should cause the clinician to search out other etiologies. An injury over the posterior legs and buttocks suggests the child was placed into the hot water by her caregiver. If she stepped into the water, she would have a burn over the lower legs and feet, as well as on her buttocks if she sat down in the water. Social services should be notified in all cases of suspected child abuse. ⚠Choice A is not correct: Follow-up care is appropriate, but social services must be contacted first. ⚠Choice B is not correct: Superficial burns should not be managed with hot compresses, but rather cool, loosely wrapped bandages. ⚠Choice D is not correct: A parent whose child had been involved in an accidental injury would certainly require reassurance and counseling, but the pattern of the child's burns indicates that this injury was not accidental. ⚠Choice E is not correct: Referring the parents to family counseling may also be an important intervention. However, social services should be notified first. 🔖 Summarized Points: Child abuse and neglect should be considered when a child's injuries seem unlikely given the reported circumstances. Social services should be notified in all cases of suspected child abuse.

A 2-year-old girl is brought to the hospital by her father because of an acute burn. She is developmentally delayed and is crying loudly. Her father says he was getting her ready for a bath and had not yet tested the water's temperature. However, the child climbed in and burned herself. Physical examination reveals a disheveled child with dirt on her face and intertriginous areas. Examination of the burn area reveals intact bright red, edematous skin extending over the child's buttocks and covering the posterior upper thighs. Which of the following is the most appropriate next step in management? A. Arrange for follow-up care B. Bandage lower limbs with hot compresses C. Contact social services D. Reassure and educate the parent E. Refer parent to family counseling

The correct answer is E. This patient has benign paroxysmal positional vertigo (BPPV), as manifested by brief episodes of vertigo that most often occur with certain head positions. Characteristically, other vestibulocochlear symptoms such as hearing loss or tinnitus are absent. On examination these patients have positional nystagmus, usually when the head is turned into the position that causes vertigo. The condition results from otolith debris accidentally entering one of the semicircular canals and brushing against the sensory cilia. The Dix-Hallpike maneuver will reproduce symptoms. This condition is improved by simple bedside maneuvers such as the Epley maneuver. During this maneuver, the patient's head is turned in a certain direction so that otolith debris moves toward the utricle, and the sequence of movements is repeated until no nystagmus is elicited. ⚠Choice A is not correct: An FM clock-radio tuned between stations at night is a controversial treatment used for patients with severe tinnitus that is especially bothersome at night. ⚠Choice B is not correct: Intratympanic gentamicin is a treatment for severe Meniere's disease that is not responsive to traditional treatment. ⚠Choice C is not correct: A low-salt diet and diuretics are the treatment of choice for Meniere's disease, in which patients present with vertigo, hearing loss, tinnitus, and aural fullness. ⚠Choice D is not correct: Methylprednisolone is used to treat vestibular neuritis, a viral condition that causes nausea and vomiting in addition to vertigo. Summarized Points: Benign paroxysmal positional vertigo presents with brief episodes of vertigo that occur only with certain head positions. It occurs as a result of otolith debris entering the semicircular canals. These patients have a positive Dix-Hallpike maneuver, in which head manipulations will reproduce their symptoms. Treatment includes the Epley maneuver and symptoms usually resolve in a few months.

A 42-year-old woman presents to her primary care physician with complaints of vertigo. She states that the episodes are severe and typically occur when she tilts her head backward. The episodes usually last several seconds to a minute, and most commonly occur while she is in bed. There is no associated hearing loss or tinnitus. Her temperature is 36.7 C (98.1 F), heart rate is 83/min, blood pressure is 125/80 mm Hg, and respiratory rate is 16/min. Apart from positional nystagmus, her neurologic examination is within normal limits.  What is the most appropriate management for this patient's condition? A. An FM clock-radio tuned between stations at night B. Intratympanic gentamicin C. Low-salt diet and diuretics D. Methylprednisolone E. Epley maneuver

To manage her symptoms, she was put on dietary restrictions. She has maintained a daily intake of sodium of <1000 mg for the past 6 weeks. She does not drink or smoke tobacco. However, her symptoms of vertigo, tinnitus, and associated nausea have not been alleviated. Which of the following is the most effective next step in management?   A. Intracochlear gentamicin injection B. Labyrinthectomy C. Metoclopramide D. Sacculotomy E. Trial of diuretics

The correct answer is C. The most appropriate physical examination maneuver to test for complete rupture of the Achilles tendon is the Thompson test, which has a sensitivity of 96% and specificity of 93%. With the patient lying in the prone position, feet hanging off the table, the clinician should squeeze the patient’s calf muscles and observe for the presence of plantar flexion of the foot. If plantar flexion is not observed on calf squeeze, the test is positive and indicates complete rupture of the Achilles tendon. ⚠Choice A is not correct: Tinel’s test is performed at the elbow or wrist to test for signs of nerve entrapment. It is performed by repetitively tapping an area of suspected nerve entrapment to elicit a tingling response in that nerve distribution. ⚠Choice B is not correct: Absence of active plantar flexion is not as reliable as the calf-squeeze test to rule out Achilles tendon rupture because the patient can also use accessory muscles (fibularis longus, fibularis brevis, plantaris, and tibialis posterior) to actively plantar flex and falsely reassure the clinician. ⚠Choice D is not correct: This test is for spine in which examiner passively flexes, abducts, and externally rotates the involved leg until the foot rests on the top of the knee of uninvolved lower extremity; examiner slowly abducts the involved lower extremity towards the table. The positive test is indicative of iliopsoas tightness, sacroiliac dysfunction, or hip joint abnormalities. ⚠Choice E is not correct: Lhermitte sign/ Barber chair phenomenon is flexion of neck producing electric shock like sensations that extend down the spine and shoot into the limbs. indicates spinal canal stenosis, disc impingement, multiple sclerosis, or tumor. Summarized Points: Complete rupture of the Achilles tendon is a clinical diagnosis that can be supported with a positive Thompson test, which is >90% sensitive and specific. The Thompson test observes for plantar flexion of the foot when the calf muscle is squeezed. The absence of plantar flexion signifies complete rupture and a positive test result.

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A 45-year-old man limps into the emergency department favoring his left leg. He states that he was playing a game of pick-up basketball this afternoon when he jumped for the ball; upon landing he felt a “snap” in his left calf and the sudden onset of pain. Initially he thought it was a sprain since he does not exercise regularly, but he became concerned given the persistence of the pain and the difficulty he has walking and climbing stairs. He does not use tobacco, alcohol, or illicit drugs. His father has a history of rheumatoid arthritis. His blood pressure is 110/70 mmHg, pulse is 90 /min, respiratory rate is 16/min, temperature is 37 C. Which of the following is the most accurate test to confirm complete Achilles tendon rupture in this patient? A. Tinel’s test B. Absence of active plantar flexion C. No plantar flexion on calf squeeze D. FABER/Patrick’s test E. Lhermitte sign

The correct answer is E. This patient's eye lesion is consistent with a hordeolum, which refers to a focal, acute, purulent inflammation at the eyelid margin. An internal hordeolum results from inflammation of a meibomian gland on the conjunctival side of the eyelid. In contrast, an external hordeolum (stye) arises from an eyelash follicle or tear gland. Treatment is aimed at encouraging drainage of the lesion with application of warm, moist compresses to the affected eye several times a day until the condition resolves. In addition, patients with styes should be instructed not to wear contact lenses or eye makeup as this can further exacerbate the inflammation. ⚠ Choice A is not correct: A hordeolum that does not resolve may harden into a chalazion (painless, rubbery, nodular lesion). Incision and drainage by an ophthalmologist is reserved for recalcitrant lesions. ⚠ Choice B is not correct: A course of oral antibiotics is indicated for preseptal cellulitis, which manifests as diffuse periorbital erythema, edema, and pain. This patient’s symptoms are localized to a very small area and not concerning for preseptal cellulitis; oral antibiotics are not indicated. ⚠ Choice C and D are not correct: All ointment containing antibiotics and steroids is used for blepharitis (chronic eyelid inflammation). However, these medications have not been shown to expedite healing in patients with a hordeolum. Summarized Points: A hordeolum is a small area of acute eyelid inflammation. Warm, moist compresses can be applied to promote drainage, but antibiotics are not indicated. A hordeolum can harden into a chalazion, which may require incision and drainage.

The correct answer is E. This patient's eye lesion is consistent with a hordeolum, which refers to a focal, acute, purulent inflammation at the eyelid margin. An internal hordeolum results from inflammation of a meibomian gland on the conjunctival side of the eyelid. In contrast, an external hordeolum (stye) arises from an eyelash follicle or tear gland. Treatment is aimed at encouraging drainage of the lesion with application of warm, moist compresses to the affected eye several times a day until the condition resolves. In addition, patients with styes should be instructed not to wear contact lenses or eye makeup as this can further exacerbate the inflammation. ⚠ Choice A is not correct: A hordeolum that does not resolve may harden into a chalazion (painless, rubbery, nodular lesion). Incision and drainage by an ophthalmologist is reserved for recalcitrant lesions. ⚠ Choice B is not correct: A course of oral antibiotics is indicated for preseptal cellulitis, which manifests as diffuse periorbital erythema, edema, and pain. This patient’s symptoms are localized to a very small area and not concerning for preseptal cellulitis; oral antibiotics are not indicated. ⚠ Choice C and D are not correct: All ointment containing antibiotics and steroids is used for blepharitis (chronic eyelid inflammation). However, these medications have not been shown to expedite healing in patients with a hordeolum. Summarized Points: A hordeolum is a small area of acute eyelid inflammation. Warm, moist compresses can be applied to promote drainage, but antibiotics are not indicated. A hordeolum can harden into a chalazion, which may require incision and drainage.

A 14-year-old boy is brought to the office due to right eye pain. Yesterday, she developed swelling on the right upper eyelid. Examination shows a tender, 3 mm area of swelling and erythema along the margin of the right upper eyelid. There is no conjunctival injection or discharge. Extraocular movements are intact and her visual acuity is 20/20 bilaterally. Which of the following is the most appropriate management of this patient's condition? A. Incision and drainage of the lesion B. Oral antibiotics C. Topical antibiotics D. Topical corticosteroids E. Application of warm compresses

This patient traveled to a Lyme endemic area and subsequently developed systemic symptoms and a rash with central clearing, raising strong suspicion for early localized Lyme disease. Lyme disease is a spirochetal illness caused by Borrelia burgdorferi and is transmitted during blood feeding by the bodes scapular's tick. Although patients may not recall a tick bite, symptoms of early localized Lyme disease typically occur 7-14 days after inoculation, including: Erythema migrans (EM), a macular rash that slowly spreads outward and eventually forms areas of central clearing (leading to a "bull's eye" appearance) Nonspecific systemic manifestations such as headache, malaise, low-grade fever, and myalgia Because the humoral antibody response is not yet formed at this early stage of disease, serologic testing should not be performed. Patients are diagnosed clinically, primarily based upon residence/travel to a Lyme endemic area and the presence of the hallmark lesion of EM. Empiric treatment with 14 days of oral doxycycline is the preferred therapy for patients of all ages (including children) due to high efficacy and activity against possible coinfection with Anaplasia (also transmitted by / scapular's). Oral amoxicillin is also effective but is generally reserved for pregnant patients or those with allergies to doxycycline. ⚠Choice A is not correct: IgM antibodies for Lyme disease may take 2-6 weeks after infection to appear in the blood. Patients (such as this patient) presenting initially with EM do not require serologic testing and should be treated for Lyme disease with antibiotics (e.g., doxycycline, cefuroxime, or amoxicillin). ⚠Choice B is not correct: Intravenous ceftriaxone is effective against B burgdorferi but is reserved for patients with more serious complications who need to be hospitalized (e.g., meningitis, carditis). Oral agents are preferred for early localized Lyme disease and for most patients who can be treated as outpatients. ⚠Choice C is not correct: Low-dose prednisone often rapidly reverses symptoms in patients with polymyalgia rheumatica, an autoimmune disease marked by symmetric muscle pain and limited movement in the shoulder and pelvic girdles. Although systemic symptoms can sometimes occur, a rash with central clearing would be atypical. ⚠Choice D is not correct: Viral respiratory infections often cause nonspecific systemic symptoms, but most patients would have some manifestations linked to the upper airways (e.g., cough, rhinorrhea). The presence of a single macular lesion with central clearing makes viral upper respiratory infection less likely than Lyme disease. Summarized Points: Early localized Lyme disease should be suspected in any patient who recently visited or resides in a Lyme endemic area and presents with the hallmark rash of erythema migrans. Serology should not be performed at this early stage of illness due to a lack of full humoral response. The diagnosis is made clinically, and oral doxycycline is the treatment of choice for all nonpregnant patients.

A 72-year-old woman comes to the office due to 2 days of malaise, fatigue, and fleeting joint pains in her neck and shoulders. She is retired and frequently travels with her ornithology club to view birds along Lake Erie beach. Temperature is 37.9 C (100.2 F), blood pressure is 128/68 mm Hg, and pulse is 102/min. Palpation of the patient's cervical spine and paraspinous muscles reveals no reproducible tenderness. There is a flat, erythematous, 4-cm lesion with a pale center on her right thigh. Which of the following is the most appropriate next step in the management of this patient? A. Borrelia burgdorferi serology B. Intravenous ceftriaxone C. Low-dose prednisone D. Viral respiratory panel E. Oral doxycycline

The correct answer is E. von willebrand's disease (vWD) is a coagulation disorder due to a deficiency in von Willebrand’s factor (vWF). vWF is necessary for platelet-to-platelet adhesion and platelet adhesion to epithelial surfaces. In addition, vWF stabilizes coagulation factor VIII in the circulation and prevents its degradation. Patients with vWD may present with easy bruising or mucosal bleeding (oral, gastrointestinal, or menstrual bleeding). These patients do not develop petechiae or hemarthrosis, as may be seen with other coagulation disorders. vWD is usually inherited through an autosomal dominant pattern. The laboratory findings show a normal platelet count with increased bleeding time, as would be expected in a case of vWD. In addition, the patient has low factor VIII activity and a prolonged partial thromboplastin time, which is due to increased factor VIII degradation as seen with vWF deficiency. ⚠Choice A is not correct: Factor VIII inhibitor is a common condition that can mimic hemophilia. In patients with a factor VIII inhibitor, the partial thromboplastin time will not correct, as it did in this patient. Therefore, a factor VIII inhibitor is unlikely. ⚠Choice B and C are not correct: Hemophilia type A and B are associated with deficiencies or impaired function of coagulation factor VIII and IX respectively. These patients present with an increased partial thromboplastin time. It is expected that hemophilia patients would have a normal bleeding time because their platelet function is not altered. In addition, these patients may present with hemarthrosis. Hemophilia is an x-inked recessive disease that does not typically affect female patients. ⚠Choice D is not correct: Given this patients presentation and family history of bleeding, a medication adverse effect is unlikely. Thrombocytopenia is a common adverse effect of medications such as methotrexate, valproic acid, histamine blockers (H2), and more. However, this patient has a normal platelet count. Dysfunction of platelet function and the coagulation profile is possible, but a young patient with no medical history is unlikely on a medication like aspirin. Summarized Points: von willebrand's disease (vWD) is a coagulation disorder generally inherited through an autosomal dominant pattern that presents with easy bruising or mucosal bleeding. Laboratory findings in this disorder show a normal platelet count with increased bleeding time

A 27-year-old woman presents with complaints of daily nosebleeds and heavy menstrual cycles. She says she has had a history of easy bruising but no other medical problems. She states her father, sister, and brother also bruise easily. The patients mother does not share these symptoms, and further questioning reveals no bleeding or coagulation disorders in any of her relatives. Physical examination reveals ecchymoses on the arms and gingival bleeding. No petechiae or hemarthrosis are noted. The remainder of the physical examination is noncontributory. Laboratory tests show:   White blood cells 9 x 109/L (3.5–10.5)   Hemoglobin 125 g/L   Platelet 205 x 109/L (130–380)   Bleeding time 9 minutes (1–9)   Prothrombin time 12 seconds (10–14)   Mixing study prothrombin time 15 seconds    Partial thromboplastin time 47 seconds (22–30)   Mixing study partial thromboplastin time 37 seconds    Factor VIII coagulant activity low   Which of the following is the most likely diagnosis? A. Factor VIII inhibitor B. Hemophilia type A C. Hemophilia type B D. Medication adverse effect E. von Willebrand’s disease