PANCE Review for Physician Assistant Certification Exam Prep + CME

Educational Objective:

No antibiotic prophylaxis is indicated for dental procedures in low risk patients.

Key Point:

Antibiotic prophylaxis before a dental procedure is only indicated in high risk patients. Patients with mitral valve prolapse and other valve abnormalities do not fulfill criteria for high risk and do not benefit from the use of antibiotics.

Explanation:

The American Heart Association (AHA) published revised guidelines in 2007 in which they markedly limited the recommendations for the use of antimicrobial prophylaxis for the prevention of infective endocarditis (IE), except for patients who are at highest risk of adverse outcomes such as patients with prosthetic heart valves,  prior history of infective endocarditis, unrepaired cyanotic congenital heart disease, repaired congenital heart defects with prosthetic material (within 6 months of the procedure); repaired congenital heart disease with residual defects and/or valve regurgitation in a transplanted heart . They recommended against prophylaxis in patients with MVP.

Reference:

Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP 3rd, Fleisher LA, Jneid H, Mack MJ, McLeod CJ, O’Gara PT, Rigolin VH, Sundt TM 3rd, Thompson A. 2017 AHA/ACC focused update of the 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation: 2017.

Current guidelines recommend that PD-related psychosis be managed with quetiapine or clozapine. Levodopa increases dopamine, which can result in psychiatric symptoms. Antipsychotics inhibit dopamine, which can result in PD symptoms.

The balance is difficult to manage between increased motor symptoms due to the antipsychotic antagonism of dopamine and the control of psychiatric symptoms due to the increased dopamine from levodopa. However, the decision must eventually be made to make one of the issues the primary target.

Because quetiapine causes fewer motor symptoms than other atypical antipsychotics, it is a drug of choice for the management of PD psychosis. Clozapine is the other drug of choice, but it has a larger adverse-event profile and more stringent monitoring parameters than the other choices.

Reference:

Miyasaki JM, Shannon K, Voon V, et al. Practice parameter: evaluation and treatment of depression, psychosis, and dementia in Parkinson disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2006;66:996-1002.

Educational Objective:

Describe the risk of rubella in pregnancy.

Key Point:

Until roughly the 20th week of pregnancy, rubella can cause infant hearing loss, mental retardation, and congenital heart and ocular defects.

Explanation:

The patient’s presentation is more consistent with rubella (German measles) than classic measles (rubeola). Rubella tends to present with lower fevers than measles, a more benign course, and a more pinkish, finer rash than the redder, more coalesced rash of classic measles. The most important concern is the fact that the patient is in her first trimester of pregnancy, because, up until roughly the 20th week of pregnancy, rubella can cause hearing loss, mental retardation, and congenital heart and eye defects.

The other options listed are classic presentations of classic measles (rubeola), not rubella. In patients with rubeola, leukopenia is expected; leukocytosis implies superimposed bacterial infection. Respiratory complications and pneumonia occur in a significant minority of rubeola cases. Encephalitis occurs in about 1 in 1000, with a high incidence of permanent brain damage or death. Subacute sclerosing panencephalitis (SSPE) is a late but lethal sequela in about 1 in 100,000 cases of rubeola. SSPE may also be seen after receiving the killed vaccine virus.

The actual rashes of rubella, rubeola, and roseola are nearly indistinguishable; the clinical context is needed to help with suspecting the right diagnosis (see Figure).

Figure. Image courtesy of the Centers for Disease Control and Prevention.

Reference:

American Academy of Pediatrics. Rubella (section 3). In: Kimberlin DW, et al, eds. Red Book: 2018 Report of the Committee on Infectious Diseases. 2018:705-711.

Cherry JD, Adachi K. Rubella virus (chapter 173). In: Cherry J, Demmler-Harrison GJ. Feigin and Cherry’s Textbook of Pediatric Infectious Diseases. 8th ed., 2018:2195-2225.

There remains some controversy regarding the best first-line test for suspected pheochromocytoma and both 24-hour urine collection for metanephrines and plasma-free metanephrine levels are used for initial evaluation. The 2014 Clinical Practice Guideline from the Endocrine Society continue to recommend the use of either 24-hour urine collection for metanephrines or plasma-free metanephrine levels for initial investigation when a diagnosis of pheochromocytoma is suspected. However between these two testing modalities, abnormal measurements of plasma-free metanephrines are more sensitive for pheochromocytoma. Plasma concentrations of normetanephrine higher than 2.5 pmol/mL or metanephrine levels higher than 1.4 pmol/mL indicate pheochromocytoma with almost 100% sensitivity. The specificity is lower at around 85% and hence there is a high rate of false positive.

A 24-hour urine collection for metanephrines has a sensitivity of 90% but the specificity is higher than that of plasma-free metanephrine levels at around 95%. The accuracy of the 24-hour urinary levels for metanephrines can be improved by indexing urinary metanephrine levels by urine creatinine levels.

The differences in sensitivity and specificity between these two tests has led some to recommend plasma fractionated metanephrines among patients at high risk for pheochromocytoma, and 24-hour urine metanephrines for those at low risk.

The clonidine suppression test is useful for distinguishing between high levels of plasma norepinephrine caused by release from sympathetic nerves and those caused by release from pheochromocytoma.

A decrease of at least 50% in plasma norepinephrine levels after clonidine administration is normal, whereas persistent elevations are indicative of pheochromocytoma.

References:

Lenders JW, Duh QY, Eisenhofer G, et al. Pheochromocytoma and paraganglioma: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2014 Jun;99(6):1915-1942.

Lenders JWM, Eisenhofer G. Update on Modern Management of Pheochromocytoma and Paraganglioma. Endocrinol Metab (Seoul). 2017;32(2):152-161.

Young WF. Clinical presentation and diagnosis of pheochromocytoma. Updated September 2016. Accessed July 20^th, 2017.

This patient likely has secondary syphilis manifested by a maculopapular rash affecting the palms and soles; she also has evidence of meningitis. The initial chancre ulcer is usually painless and many patients may overlook it.

Compromise of the central nervous system in syphilis can occur in the setting of secondary or tertiary syphilis. Asymptomatic infiltration of the brain and meninges can also occur. In other cases, a person may develop frank meningitis with or without compromise of the cranial nerves. The CSF shows lymphocytic pleocytosis and elevated protein. Typically, results from the Venereal Disease Research Laboratory test will be positive in the CSF. Patients can also develop a meningovascular form of the disease with frank vasculitis that causes strokes. Uveitis and otosyphilis (characterized by hearing loss with or without tinnitus) are also manifestations of secondary syphilis.

Compromise of the central nervous system in tertiary syphilis is now rarely seen. Manifestations include general paresis (dementia) and tabes dorsalis (a disease affecting the posterior aspect of the spinal cord causing ataxia and severe lower extremity pain).

Borreliosis is transmitted by tick bites and can occasionally cause meningitis. The typical rash involves a bull’s eye lesion as the primary manifestation and may be potentially followed by a disseminated rash. However, compromise of the hands and soles is unusual.

Leptospirosis can also cause aseptic meningitis. The disease is acquired by exposure to water contaminated with animal urine or feces. Patients usually have a biphasic course with a severe febrile illness with bacteremia followed by a more immune-mediated subacute condition with nephritis, hepatitis, and hemorrhage. Conjunctival suffusion is a common manifestation, but a rash is relatively rare.

References:

Golden MR, Marra CM, Holmes KK. Update on syphilis: resurgence of an old problem. JAMA. 2003;290(11):1510-1514.

Shapiro ED. Clinical practice. Lyme disease. N Engl J Med. 2014;370(18):1724-1431.

Sperber SJ, Schleupner CJ. Leptospirosis: a forgotten cause of aseptic meningitis and multisystem febrile illness. South Med J. 1989;82(10):1285-1288.

“Secondary Stage Syphilis Sores (Lesions) on the Palms of the Hands. Referred to as ‘Palmar Lesions.".”Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 2 Aug. 2012