12 results
Causes of False-Positive and False-Negative IGRA and TST Results

#Diagnosis #TB #Tuberculosis #Tuberculin #SkinTest #TSTs #IGRA #FalseNegatives
Causes of False-Positive ... Tuberculin #SkinTest #TSTs ... #IGRA #FalseNegatives ... #FalsePositives ... #Causes
Causes of Inaccurate Fecal Occult Blood Test Results 

False Positive gFOBT:
Ingestion of nonhuman heme (eg, meat
Causes of Inaccurate ... Fecal Occult Blood Test ... OccultBlood #Testing #Laboratory ... #FalsePositive ... #FalseNegative #
Urine Drug Screens - Common drugs that may cause false positive tests 

Amphetamines:
Bupropion, Labetalol, Methylphenidate, Phenylephrine,
drugs that may cause ... false positive tests ... DrugScreens #UDS #Laboratory ... Toxicology #Diagnosis #FalsePositive
Hyponatremia - Diagnostic Evaluation Algorithm

Step 1: Consider whether Posm may actually be normal or elevated
Step 2:
Hyponatremia - Diagnostic Evaluation ... Algorithm Step ... Consider additional tests ... considered likely, the cause ... #Algorithm
What is Fecal Occult Blood Testing (FOBT)
 • Screening for colorectal cancer in average risk population
immunochemical test ... for GIB/anemia evaluation ... #FOBT #Guaiac #FalsePositives ... #FalseNegatives
Adrenal Insufficiency Diagnosis Algorithm - Evaluation of HPA Axis Response to ACTH

Early am cortisol < 3
Insufficiency Diagnosis Algorithm ... - Evaluation of ... unclear (often the case ... Standard Stim test ... #Stimulation #Test
Primary Adrenal Insufficiency:
 • ACTH stimulation test - Synthetic ACTH does not stimulate cortisol secretion because
ACTH stimulation test ... aldosterone - Low in cases ... - Serum tests that ... Insufficiency #Evaluation ... #laboratory #diagnosis
TTP - Laboratory Evaluation for Thrombotic Thrombocytopenic Purpura

Activity of von Willebrand factor-cleaving protease activity - A
TTP - Laboratory ... Evaluation for ... value is low, tests ... decrease in most cases ... indirect antiglobulin tests
Allopecia - Differential Diagnosis Framework for Hair Loss

Localized / Focal Hair Loss Pattern:
 • Scarring Alopecia:
disease • Pull test ... fungi Initial Laboratory ... Tests: • TSH ... • RPR • Laboratory ... evaluation for
Algorithm regarding the diagnosis and treatment of Hereditary Hemochromatosis HH. 

Step 1: In the patient with
Algorithm regarding ... initial screening test ... normal, further evaluation ... C282Y homozygote, evaluation ... hemochromatosis #algorithm