What is the utility of bedside skin-fold test in diagnosing Cushing’s syndrome?

Skin atrophy is a common feature of Cushing’s syndrome (CS), a hypercortisol state,  with multiple studies reporting radiographic evidence of reduced skin thickness in this condition1,2.

Measurement of skin thickness on the dorsal aspect of the 2nd or 3rd proximal phalanges on the non-dominant hand by using ECG calipers to pinch together a fold of skin has also been reported to assess skin atrophy in CS, with thickness less than 18 mm correlating strongly with CS3,4; the minimal subcutaneous fat at this location allows for a more accurate measurement of skin thickness.

However, caution should be exercised in interpreting the results of this study. Specifically, some overlap was observed between normal controls and patients with CS.  In addition, the study population was limited to women of reproductive age presenting with oligomenorrhea and hirsutism for at least 2 years, a subset of patients that may account for only 40% of cases with CS5,6.  Further studies are clearly needed to determine the clinical utility of the skin-fold test in patients suspected of CS.

References

  1. Sheppard RH, Meema HE. Skin thickness in endocrine disease. A roentgenographic study. Ann Intern Med 1967;66:531-9.
  2. Ferguson JK, Donald RA, Weston TS, et al. Skin thickness in patients with acromegaly and Cushing’s syndrome and response to treatment. Clin Endocrinol (Oxf) 1983;18:347-53.
  3. Corenblum B, Kwan T, Gee S, et al. Bedside assessment of skin-fold thickness: A useful measurement for distinguishing Cushing’s disease from other causes of hirsutism and oligomenorrhea. Arch Intern Med. 1994;154:777-781.
  4. Loriaux DL. Diagnosis and differential diagnosis of Cushing’s syndrome. N Engl J Med 2017;376:1451-9.
  5. Lindholm J, Juul S, Jorgensen JOL, et al: Incidence and late prognosis of Cushing’s syndrome: a population-based study. J Clin Endocrinol Metab 2001;86:117–123.
  6. Lado-Abeal J, Rodriguez-Arnao J, Newell-Price JD, et al. Menstrual abnormalities in women with Cushing’s disease are correlated with hypercortisolemia rather than raised circulating androgen levels. J Clin Endocrinol Metab. 1998;83:3083-8.

Contributed by Sagar Raju, Medical Student, Harvard Medical School

What is the utility of bedside skin-fold test in diagnosing Cushing’s syndrome?

“In my patient with abdominal pain, what physical exam finding can help differentiate abdominal wall from intra-abdominal sources of pain?”

Most doctors have received the following page at some point in their career: “Patient having abdominal pain, please come assess.” Carnett’s sign (described by British surgeon J.B. Carnett in 1926) is a physical exam finding that helps differentiate abdominal wall from intra-abdominal sources of pain. Once the tender spot is located, the test is considered positive when the patient’s pain increases upon tensing of the abdominal wall muscles– such as by raising both legs with straight knees or lifting the head and shoulders from the bed. Conversely, if the pain decreases with this maneuver, an intra-abdominal source is more likely1,2.

A positive Carnett’s sign should broaden the differential of abdominal pain to include: hernias, irritation of intercostal nerve roots, rectus sheath hematomas, myofascial pain, anterior cutaneous nerve entrapment (latter discussed in another pearl). In the appropriate clinical setting,  local corticosteroids or anesthetic injections, or the application of hot or cold packs may be therapeutic2,3.

 References

  1. Carnett JB. Intercostal neuralgia as a cause of abdominal pain and tenderness. J Surg Gynecol Obstet 1926; 42:625-632.
  2. Bundrick JB, Litin SC. Clinical pearls in general internal medicine.  Mayo Clin Proceedings 2011;86: 70–74. 
  3. Suleiman S , Johnston DE.  The abdominal wall: an overlooked source of pain. Am Fam Physician 2001; 64: 431-8.

Contributed by Brad Lander MD, Mass General Hospital, Boston, MA.

“In my patient with abdominal pain, what physical exam finding can help differentiate abdominal wall from intra-abdominal sources of pain?”

Does electroconvulsive therapy (ECT) pose a risk of embolic stroke in patients with atrial fibrillation (AF)?

Acute embolic stroke in the setting of AF without anticoagulation after ECT has been reported in a single case report in the absence of conversion to normal sinus rhythm (1). Several cases of episodic or persistent conversion to normal sinus rhythm (NSR) in patients with AF undergoing ECT have also been reported (in the absence of embolic stroke), leading some to recommend anticoagulation therapy in such patients (2), though no firm data exist.

The mechanism by which ECT promotes cardioversion from AF to NSR is unclear as direct electrical influence of ECT on the heart is thought to be negligible (1). Arrhythmias such as atrial flutter and AF have also been reported after ECT (1). Curiously, ECT is associated with increased 5- hydroxytryptamine (5- HT2)-receptor densities of platelets in patients with depression which may enhance platelet reactivity and increase the risk of embolic stroke (3) even in the absence of cardioversion.

 

References

  1. Suzuki H, Takano T, Tominaga M, et al. Acute embolic stroke in a patient with atrial fibrillation after electroconvulsive therapy. J Cardiol Cases 2010; e12-e14.
  2. Petrides G, Fink M. Atrial fibrillation, anticoagulation, electroconvulsive therapy. Convulsive Therapy 1996;12:91-98.
  3. Stain-Malmgren R, Tham A, Ǻberg-Wistedt A. Increased platelet 5-HT2 receptor binding after electroconvulsive therapy in depression. J ECT 1998;14:15-24.
Does electroconvulsive therapy (ECT) pose a risk of embolic stroke in patients with atrial fibrillation (AF)?

Which motor test may be the most useful maneuver when examining a patient suspected of having a stroke?

When limited by the number of motor tests that can be performed on a patient suspected of having a stroke, the pronator drift may be your best bet! This test may be positive in as many as 94% of patients within a week of having a stroke (1).  An advantage of this maneuver is that it can point to subtle lesions in the corticospinal tract (CST) often missed by formal strength testing.

To perform the test, ask the patient to hold his or her arms straight out in front with palms facing upwards and eyes closed for 20-30 seconds. Slight pronation of one hand and flexion of the elbow suggests mild drift. Additional downward drift of the entire arm may also be present with more severe deficits (2). Interestingly, if one arm drifts upward this suggests a lesions outside the CST, possibly a cerebellar or parietal lesion, which may be equally concerning.

 

References

  1. Louis ED, King D, Sacco R, et al. Upper motor neuron signs in acute stroke: prevalence, interobserver reliability, and timing of initial examination. J Stroke Cerebrovasc Dis 1995;5:49-55.
  2. Campbell, WW. In DeJong’s The Neurologic Examination-6th Ed, p389-392, 2005. Lippincott Williams&Wilkins, Philadelphia.

 

 

 

Contributed by Alexis Roy, Harvard Medical Student, Boston, MA.

Which motor test may be the most useful maneuver when examining a patient suspected of having a stroke?

What is the clinical utility of neck stiffness, Kernig’s sign and Brudzinski’s sign in the evaluation of patients suspected of having meningitis?

The sensitivity of these signs for meningitis is poor: neck stiffness 30% and Kernig’s and Brudzinski’s signs 5% each (1).  Therefore, their absence does not exclude the possibility of meningitis. Although their specificities may be comparatively better (neck stiffness 68%, and Kernig’s and Brudzinski’s signs 95% each), the positive and negative predictive values of these signs generally leave a lot to be desired and their likelihood ratios (both positive and negative) are poor (near 1.0) (1).  

The poor sensitivities of Kernig’s and Brudzinski’s signs may be related to the fact that the original research papers published over 100 years ago involved primarily children with severe bacterial or tuberculous meningitis, a population that is quite different than today’s elderly or immunocompromised patients (2) who may present earlier during their course of disease. Thus, the decision to perform a lumbar puncture should be based primarily on factors other than these signs.

 References

  1. Thomas KE, Hasbun R, Jekel J, et al. The diagnostic accuracy of Kernig’s sign, Brudzinski’s sign, and nuchal rigidity in adults with suspected meningitis. Clin Infec Dis 2002;35:46-52.
  2. Mehndiratta M, Nayak R, Garg H, et al. Appraisal of Kernig’s and Brudzinski’s sign in meningitis. Ann Indian Acad Neurol. 2012 Oct-Dec; 15(4): 287–288.
What is the clinical utility of neck stiffness, Kernig’s sign and Brudzinski’s sign in the evaluation of patients suspected of having meningitis?

What is the utility of pulmonary auscultation for crackles (rales) in diagnosing congestive heart failure (CHF) or pneumonia?

The evidence for the accuracy of crackles in CHF is not as robust as often assumed, with wide variations in its sensitivity (13%-70%), specificity (35%-100%), positive predictive value (19%-100%), and negative predictive value (17%-85%) (1). In a study  of patients at high risk for CHF but without valvular heart disease, symptoms of CHF, or comorbid pulmonary disease,  the prevalence of baseline crackles in one or both lungs increased with age: 45-64 y , 11%; 65-79 y, 34%; and 80-95 y, 70%.  Overall, an at best fair or poor negative likelihood ratios (LRs) have been reported for crackles in CHF (3.4, and 0.8, respectively)(2). 

The accuracy of crackles in diagnosing pneumonia in patients with cough and fever is not much better: sensitivity 19-67%, specificity 36-94%, and poor positive and negative LRs (1.8 and 0.8, respectively) (2).

So don’t overestimate the accuracy of crackles in CHF or pneumonia!

  1. Kataoka H, Matsuno O. Age-related pulmonary crackles (rales) in asymptomatic cardiovascular patients. Ann Fam Med 2008;6:239-245.
  2. McGee S. Auscultation of the lungs. In Evidence-based physical diagnosis (3rd ed.). Elsevier Saunders, Philadelphia, 2012.
What is the utility of pulmonary auscultation for crackles (rales) in diagnosing congestive heart failure (CHF) or pneumonia?

What is the significance of the ear lobe crease or “Frank’s sign”?

Frank’s sign, a diagonal earlobe crease, is one of numerous extra-cardiac signs of coronary artery disease (CAD), originally described in patients 60 years of age or younger (1). The majority of clinical, angiographic, and postmortem reports seem to support the association of this signs with atherosclerotic coronary disease (1). Although the mechanism for this association is unclear, free radical oxidative stress involved in atherogenesis has been suggested as a possible explanation through its activation of the metalloproteinases that break down type 1 collagen (2). It is fair to conclude, however, that the value of this sign as a screening tool for CAD has not been established and its utility in clinical practice remains uncertain,  particularly in those older than 60 years of age.

franks2

1. Friedlander AH, Lopez-Lopez J, Velasco-Ortega E. Diagonal ear lobe crease and atherosclerosis: a review of the medical literature and dental implications. Med Oral Patol Oral Cir Bucal 2012;1:e153-9.

2. Fabijanic D, Culic V. Diagonal ear lobe crease and coronary artery disease. Am J Cardiol 2012;110:1385-6.

Contributed by Kathryn Dinh, 4th year medical student, Harvard Medical School

What is the significance of the ear lobe crease or “Frank’s sign”?