Internal Medicine
Board Review

Educational Objective:

Recognize a type 4 drug reaction.

Key Point:

A type 4 drug reaction usually occurs 5 to 14 days after exposure to a causative drug and presents as a typical drug rash.

Explanation:

This is an example of type 4 drug reaction and is related to T-cell activation. It is a typical "drug rash" that can be treated with topical steroids, antihistamines, and, occasionally, systemic steroids. The onset of this type of rash is typically 5 to 14 days after exposure to a causative drug.

A type 1 drug reaction is immediate and caused by mast cell degranulation and can include anaphylaxis.

A type 2 drug reaction is characterized by cell destruction due to antibody binding and can often manifest as hemolysis and anemia.

A type 3 drug reaction is related to antigens activating complement, causing serum sickness or vasculitis.

Reference:

Valeyrie-Allanore L, Revus J. Drug reactions. In: Bolognia J, et al. Dermatology. 3rd ed., 2012.

Educational Objective:

Discuss the factors that influence what antiseizure drugs to use when treating epilepsy.

Key Point:

The type of seizure is the principal factor in deciding which antiseizure drug to use.

Explanation:

The first step in designing a treatment plan is to classify the patient’s seizure type. It is a generalized, focal, or an absence seizure? More than 20 antiseizure medications are currently approved in the United States for the treatment of seizures in adults and children. No single antiseizure drug has been clearly demonstrated to be the most effective or best tolerated, regardless of the type of seizure. Nearly one-half of all patients will become seizure free with their first antiseizure drug trial.

Age, sex, etiology of the seizure (when known), use of other medications, comorbid medical conditions, and the adverse-event profile of the drug should all be taken into consideration.

Although it is important to take all these variables into consideration, physicians cannot be expected to integrate them without reference to the published literature, which can be helpful in making decisions about which drug to use when first starting a patient on antiseizure medication.

Current practice indicates that levetiracetam is the drug of choice for generalized seizures (followed by valproate) and myoclonic seizures; ethosuximide for absence seizures; and lamotrigine, levetiracetam, or oxcarbazepine for focal seizures. Compared with surveys taken in 2001 and 2005, a decreased preference was observed in the use of phenytoin, gabapentin, phenobarbital, and carbamazepine.

References:

Schachter SC. Overview of the management of epilepsy in adults. Updated July 9, 2018. Accessed August 18, 2018.

Shih JJ, Whitlock JB, et al. Epilepsy treatment in adults and adolescents: expert opinion, 2016. Epilepsy Behav. 2017;69:186-222.

Educational Objective:

Assess risk factors for suicide.

Key Point:

Suicide risk can be assessed by looking at factors such as prior history, substance abuse, stressors, and psychosocial stressors.

Explanation:

Most individuals who complete suicide have a psychologic or addictive disorder. A mood disorder diagnosis imparts a fourfold increased risk of suicide, and 2 psychiatric diagnoses impart an 18-fold increased risk. Prior suicide attempts increase this risk and are the single best predictor of suicide completion. Substance abuse may trigger an event. Immediate risk factors include firearms in the home (also a good predictor of completion) and recent severe stressful life events, especially the death of a spouse or a recent diagnosis of a terminal illness.

Reference:

Betz ME, Caterino JM, Suicide. In: Walls R, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed., 2017.1366-1373.

Educational Objective:

Distinguish cardiac shock from other causes of shock.

Key Point:

Patients in cardiac shock can benefit from an intra-aortic balloon pump.

Explanation:

This patient is in cardiogenic shock most likely due to recent MI. The placement of an intra-aortic balloon pump to assist with stabilization prior to cardiac catheterization is indicated. This step is consistent with guidelines from the American College of Cardiology/American Heart Association: Patients with cardiogenic shock secondary to MI who have hypotension that does not improve with pressor support should have an intra-aortic balloon pump to assist with stabilization prior to cardiac catheterization.

The other choices listed are not in accordance with the guidelines. Although supportive care is certainly necessary, delaying cardiac catheterization could result in a higher rate of mortality.

References:

Antman EM, Anbe DT, Armstrong PW, et al; American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients With Acute Myocardial Infarction). ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction--executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients With Acute Myocardial Infarction). Circulation. 2004;110(5):588-636.

Hochman J, Reyentovich A. Prognosis and treatment of cardiogenic shock complicating acute myocardial infarction. Accessed July 18, 2016.

O'Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2013;61(4):e78-e140.

Ramanathan K, Farkouh ME, Cosmi JE, et al. Rapid complete reversal of systemic hypoperfusion after intra-aortic balloon pump counterpulsation and survival in cardiogenic shock complicating an acute myocardial infarction. Am Heart J. 2011; 162(2):268-275.

Thiele H, Zeymer U, Neumann FJ, et al. Intraaortic balloon support for myocardial infarction with cardiogenic shock. N Engl J Med. 2012;367(14):1287-1296.

Educational Objective:

Select the most appropriate test for avascular necrosis of the bone.

Key Point:

Avascular necrosis of the bone may be missed on plain x-ray. An MRI or a bone scan may offer higher sensitivity to detect the condition.

Explanation:

Avascular necrosis of the bone or osteonecrosis can be caused by damage to blood vessels feeding the bone or direct injury of the bone or the bone marrow. The use of glucocorticoids is one of the most common risk factors for developing avascular necrosis of the bone; however, other conditions such as sickle cell anemia and alcohol consumption are also important etiologic factors. Patients can be asymptomatic or can present with pain usually aggravated by weight bearing and relieved with rest. The plain x-ray may not show abnormalities. MRI is much more sensitive than the plain x-ray. Radionuclide bone scanning is another reasonable option; however, MRI is probably more sensitive.

Levels of calcium and vitamin D will be unaffected in this patient.

This patient is certainly at risk of osteoporosis and a DEXA scan may confirm this diagnosis but it will not help to identify the avascular necrosis.

References:

Larson E, Jones LC, Goodman SB, Koo KH, Cui Q. Early-stage osteonecrosis of the femoral head: where are we and where are we going in year 2018? Int Orthop. 2018 Apr 4.

Kompel A, Murakami A, Guermazi A. Magnetic Resonance Imaging of Nontraumatic Musculoskeletal Emergencies. Magn Reson Imaging Clin N Am. 2016 May;24(2):369-89.