17 results
Urine Drug Screens - Common drugs that may cause false positive tests 

Amphetamines:
Bupropion, Labetalol, Methylphenidate, Phenylephrine,
false positive tests ... DrugScreens #UDS #Laboratory ... Toxicology #Diagnosis #FalsePositive ... #Testing
Algorithm for the diagnosis of chronic diarrhea.
It is usually impractical to test and treat the many
impractical to test ... diarrhea before testing ... pick specific tests ... to sort out the ... much smaller differential
Summary of Agents Potentially Contributing to False Positives on Urine Drug Screens (UDS)
Marijuana Metabolites
 • dronabinol,
• mouthwash, short-chain ... naproxen and modern tests ... #FalsePositives ... DrugScreening #UDS #Testing ... #Laboratory #diagnosis
Causes of Inaccurate Fecal Occult Blood Test Results 

False Positive gFOBT:
Ingestion of nonhuman heme (eg, meat
Fecal Occult Blood Test ... #OccultBlood #Testing ... #Laboratory #FalsePositive ... FalseNegative #Diagnosis #Differential
Chronic Diarrhea - Workup
Osmotic:
 • Consider food diary and trial avoiding certain foods or meds, Consider
hydrogen breath test ... A/P, Consider testing ... Abdominal imaging (CT, ultrasound ... celiac and/or testing ... Workup #diagnosis #differential
Causes of Secondary Hypertension - Differential Diagnosis and Screening Testing
Common causes: 
 • Renal parenchymal disease
Hypertension - Differential ... and Screening Testing ... disease - Renal ultrasound ... Duplex Doppler ultrasound ... #Hypertension #Differential
Abnormal liver function tests algorithm.
 This figure details the initial response to abnormal liver blood tests.
liver function tests ... of liver blood tests ... decision for repeat testing ... mellitus; USS, ultrasound ... Liver #Enzymes #Differential
1,3-Beta-D-Glucan and Galactomannan Testing Sensitivity Specificity and False Positives
1,3-Beta-D-Glucan
 • Cell wall component of many fungi
Galactomannan Testing ... the use of this test ... in BAL does not differentiate ... #FalsePositives ... #Laboratory #sensitivity
Allopecia - Differential Diagnosis Framework for Hair Loss

Localized / Focal Hair Loss Pattern:
 • Scarring Alopecia:
Allopecia - Differential ... disease • Pull test ... texture at bald spots ... fungi Initial Laboratory ... Tests: • TSH
Bronchiectasis - Summary

What?
• Bronchiectasis is derived from the Greek words bronckos meaning airway and ectasis meaning
adults • Blood tests ... Pulmonary function tests ... Bronchoscopy Laboratory ... Sweat chloride test ... Bronchiectasis #pulmonary #differential