Sandbox: sadaf
Differential Diagnosis
Abbreviations: ABG = Arterial blood gases, BUN = Blood urea nitrogen, CBC = Complete blood count, CT = Computed tomography, CRP = C – reactive protein, ECG = Electrocardiogram, ESR = Erythrocyte sedimentation rate, IVP = Intravenous pyelography, KFT = Kidney function test, GI = Gastrointestinal, GFR = Glomerular filtration rate, MRI = Magnetic resonance imaging, PT = Prothrombin time
| Etiology | Clinical manifestations | Paraclinical findings | Comments | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Symptoms and signs | Lab findings | Imaging | ||||||||||||||||||||
| Fatigue/
Lethargy |
Thirst | Dizziness/
Confusion |
Muscle weakness/
cramp |
Somatic/
visceral pain |
Vomiting | Diarrhea | Tachypnea | Edema | Blood indices | Renal Funtion test | Electrolytes | Urine analysis | ABG | Other | Ultrasound | X–ray | CT | MRI | Other | |||
| Prerenal causes | Alcohol poisoning | + | – | ± | – | ± | + | ± | – | – | ↑PT | ↑BUN, ↑Cr (isopropyl alcohol) | ↓Na | NA | ↓HCO3 | Abnormal LFT | NA | NA | NA | NA | – | Administer thiamine to prevent Wernicke's encephalopathy |
| Aspergillosis | ± | – | – | – | – | – | – | ± | – | NA | NA | NA | NA | NA | Allergy test, ↑IgE (>1000 IU/dl), Direct visualization of fungal hyphae | NA | Pulmonary infiltrates, Mucus plug, Mass in the upper lobe surrounded by a crescent of air, Solitary or multiple cavities | Halo sign, Wedge–shaped pulmonary infarction, Granuloma | NA | – | Polymerase chain reaction (PCR) | |
| Cholera | ± | + | – | – | – | ± | + | – | – | Leukocytosis, ↑HCT | ↑BUN, ↑Cr | ↓Na, ↑Ca, ↑Mg | NA | ↑Lactate, ↓HCO3 | Stool PCR, Stool culture, Serotyping | NA | NA | NA | NA | – | – | |
| Congestive heart failure (CHF) | + | – | – | – | – | – | + | – | + | Anemia, Leukocytosis | ↑BUN, ↑Cr | ↓Na, ↑K | NA | ↑Lactate, ↓HCO3, | ↑BNP, ↑Troponin | Cardiomegaly, Pulmonary hypertension, Pleural effusions | Pulmonary edema | NA | Valvular heart disease | Decreased ejection fraction in echocardiography, Heart function and damage in nuclear imaging | – | |
| Dehydration | + | + | – | ± | – | ± | ± | – | – | NA | ↑BUN, ↑Cr | ↓Na, ↑K, ↓Cl | Ketones and glucose, ↑Urine specific gravity | ↑Lactate, ↓HCO3 | Hypoglycemia | NA | NA | NA | NA | – | – | |
| Diarrhea and/or vomiting | ± | ± | – | – | – | + | + | – | – | Leukocytosis with predominant neutrophilia, ↑ ESR | NA | NA | Ketones, Organic acids, Porphobilinogen, Aminolevulinic acid | NA | Stool anion gap, Stool pH < 5.5, Stool culture, Serotyping, Enzyme immunoassay (rotavirus or adenovirus), LFT, Amylase, Lipase | Normal | NA | NA | NA | – | – | |
| Drugs/toxins | ± | ± | ± | ± | ± | ± | ± | ± | ± | NA | ↑BUN, ↑Cr, ↑CK | ↑K, ↓Mg, ↓Ca, ↓P | Ingested drug, Glucose, Aminoacid, Phosphate, Ketone, Hyaline cast, RBC | ↑Lactate, Metabolic acidosis | Toxicology, Rapid immunoassay | Nephropathy | Radioopaque substances, Ingested drug packets | NA | NA | – | – | |
| Esophageal varices bleeding | ± | – | – | – | ± | – | – | – | – | Normocytic normochromic anemia | ↑BUN, ↑Cr | NA | NA | NA | NA | Velocity and direction of portal flow | Abnormal opacities outside ofesophageal wall, Posterior mediastinal or intraparenchymal mass, Dilated azygous vein | Entire portal venous system | Portrays esophageal varices as flow voids | Portal hypertension and esophageal varices in positron emission tomography, Flexible endoscope, Barium swallow of snake–like filling defects | – | |
| Heart disease | ± | – | – | – | – | – | – | ± | ± | ↑ESR and CRP | ↑BUN, ↑Cr | NA | NA | NA | Throat culture, Rapid streptococcal antigen test, Hyperoxia test, Pulse oximetry | NA | Cardiomegaly, Dextrocardia | NA | NA | Ventricular dysfunction, Left and right ventricular hypertrophy, Valvular disease in echocardiography | – | |
| Hemorrhage | – | – | – | – | – | – | – | – | – | Normocytic normochromic anemia, ↑PT, ↑PTT | ↑BUN, ↑Cr | ↑Na, ↑Cl, ↓Ca | NA | Metabolic acidosis | NA | Peritoneal cavity fluid in FAST | Bilateral opacities in the lung field, Hemothorax, Hemoperitoneum, Ruptured abdominal aortic aneurysm | Intrathoracic, intra–abdominal, and retroperitoneal bleeding | NA | Source of bleeding in the upper GI in EGD, Angiography | – | |
| Hemolysis | ± | – | – | – | – | – | – | – | – | Thrombocytopenia, Microcytic hypochromic anemia, ↑RDW, ↑Retic count | NA | NA | NA | NA | ↑LDH, ↓Haptoglobin, ↑Unconjugated bilirubin | Hepatomegaly,Splenomegaly | NA | NA | NA | – | – | |
| Etiology | Fatigue/
Lethargy |
Thirst | Dizziness/
Confusion |
Muscle weakness/
cramp |
Somatic/
visceral pain |
Vomiting | Diarrhea | Tachypnea | Edema | Blood indices | Renal Funtion test | Electrolytes | Urine analysis | ABG | Other | Ultrasound | X–ray | CT | MRI | Other | Comments | |
| Hepatorenal syndrome | ± | – | – | – | ± | ± | – | – | ± | Leukocytosis, ↑PT | ↓GFR, ↑BUN, ↑Cr | ↓Na | Proteinuria, Na < 10 mEq/L, Urine osmolality > plasma osmolality | NA | Alpha feto–protein, Cryoglobulinemia | Exclude hydronephrosis and intrinsic renal disease | NA | NA | NA | Right ventricular preload, ventricular filling pressures, and cardiac function in echocardiography | – | |
| Ischemic cardiomyopathy | ± | – | – | – | – | – | – | ± | ± | Anemia | ↑Cr | ↓Na, ↓K, ↓Mg | NA | NA | Troponin, Creatine kinase, Creatine kinase – MB, BNP | NA | Abnormal cardiac silhouette | Biventricular volume, Wall motion abnormality, Myocardial perfusion, Hypertrophic cardiomyopathy | Mid–wall fibrosis in MRI | Ejection fraction ≤35%, Pulmonary embolism, Right ventricular dilation or pericardial effusion with tamponade in echocardiography | – | |
| Liver cirrhosis | ± | – | ± | ± | ± | – | – | – | ± | NA | NA | NA | NA | NA | LFT, Aspartate aminotransferase to platelet ratio, FibroTest/FibroSure, Hepascore, FibroSpectatio | Portal blood flow velocity, Hepatic artery enlargement, Multifocal lesions or masses, Hepatic contour, Ascites, Splenomegaly | Bowel perforation, Gynecomastia, Azygos vein enlargement, Pleural effusion | Morphologic changes in the liver, Collaterals and shunts, Hyperattenuating nodule of hepatocellular carcinoma, Portal vein thrombosis | Vacular patency, Tumor invasion, Portal vein thrombosis, Steatosis | Hepatic function and portal hypertension in nuclear imaging, Hepatic perfusion and the development of shunts and tumors in angiography | Irreversible and a transplant is usually needed | |
| Malignant hypertension | ± | – | + | – | – | ± | – | ± | ± | Microangiopathic hemolytic anemia | ↑BUN, ↑Cr | ↑Na, ↑K, ↑P | Proteinuria, Microscopic hematuria | Acidosis | Cardiac enzymes, Urinary catecholamines, TSH, ↑Renin | NA | Cardiomegaly, Pulmonary edema, Rib notching, Aortic coarctation, Mediastinal widening, Aortic dissection | NA | NA | Left atrial enlargement and left ventricular hypertrophy in echocardiography | – | |
| Myocarditis | ± | – | – | – | ± | – | – | ± | – | Leukocytosis (eosinophilia),↑ESR and CRP | NA | NA | NA | NA | Cardiac enzymes, Viral antibodies | NA | NA | NA | Inflammatory edema, Degree of scarring | Endomyocardial biopsy, Echocardiography, Scintigraphy | NA | |
| Peritonitis | ± | – | ± | – | ± | ± | ± | – | – | Leukocytosis | NA | NA | NA | NA | Ascitic fluid neutrophil count > 500 cells/µL | NA | NA | NA | NA | – | – | |
| Polycythemia | ± | – | – | – | – | – | – | ± | – | ↑RBC, ↑HCT, ↑HGB, Thrombocytosis, Leukocytosis, ↑PT and aPTT | ↓Erythropoietin | NA | NA | NA | Hyperuricemia | Splenomegaly | NA | NA | NA | – | Phlebotomy is the usual treatment | |
| Respiratory distress syndrome | + | – | ± | – | – | – | – | + | – | NA | NA | NA | NA | Metabolic and respiratory acidosis | Pulse oximetry | NA | Bilateral, diffuse, reticular granular or ground–glass appearance ± Cardiomegaly | NA | NA | Patent ductus arteriosus in echocardiography | – | |
| Shock | ± | ± | ± | ± | ± | ± | – | ± | – | ↑HCT, ↑PT and aPTT, Eosinophilia, Leukocytosis | ↓GFR, ↑BUN, ↑Cr | NA | NA | ↑Lactate | LFT, ↑BNP, ↑Troponin, D–dimer, Fibrinogen | Pulmonary embolism, Pericardial effusion, Cardiac tamponade, Pneumothorax, Thoracic or abdominal aortic aneurysm in RUSH (Rapid Ultrasound for Shock and Hypotension) | Pneumonia, Pneumothorax, Pulmonary edema, Widened mediastinum, Free air under the diaphragm | Traumatic brain injury, Stroke, Spinal injury, Pneumonia, Pneumothorax, Ruptured aneurysm, Aortic dissection, Pulmonary embolism | NA | – | – | |
| Toxic megacolon | ± | ± | ± | – | + | + | ± | – | – | Leukocytosis, Anemia, ↑ESR and CRP | ↑BUN, ↑Cr | ↓Na | NA | NA | Loss of haustra, Hypoechoic and thick bowel walls, Dilated colon > 6cm, Dilatation of ileal loops | Dilated colon, Free intraperitoneal air | Bowel perforation, Abscess | NA | NA | Endoscopy and colonoscopy | – | |
| Etiology | Fatigue/
Lethargy |
Thirst | Dizziness/
Confusion |
Muscle weakness/
cramp |
Somatic/
visceral pain |
Vomiting | Diarrhea | Tachypnea | Edema | Blood indices | Renal Funtion test | Electrolytes | Urine analysis | ABG | Other | Ultrasound | X–ray | CT | MRI | Other | Comments | |
| Renal causes | Acute interstitial nephritis | ± | – | ± | – | ± | ± | ± | ± | ± | Eosinophilia | ↑BUN, ↑Cr, ↑FENa | NA | Eosinophiluria, Sterile pyuria, Microscopic hematuria, Proteinuria | NA | ↑Total IgG, ↑IgG4 | Normal–sized kidneys | NA | NA | NA | – | History of long term analgesic use |
| Acute tubular necrosis | ± | – | – | – | – | ± | – | – | ± | Anemia | ↑BUN, ↑Cr, ↑FENa | ↓Na, ↑K, ↑Mg, ↑P, ↓Ca | Pigmented, muddy brown, granular casts | NA | NA | Obstructive uropathy, Renal size, Cortical thickness, Hydronephrosis | Nephrolithiasis | Nephrolithiasis, Area of obstruction | Nephrolithiasis, Area of obstruction | Loss of tubular cells or the denuded tubules, Swollen tubular cells, Loss of the cell brush border in renal biopsy | Furosemide stress testing for staging | |
| Cancer | + | – | – | – | ± | ± | – | – | ± | Normocytic or microcytic anemia, Leukocytosis or lymphocytosis, ↑Reticulocytes, Thrombocytopenia | ↓GFR, ↑BUN, ↑Cr, ↓Erythropoietin | ↓Na, ↑K, ↓Mg, ↑P, ↓Ca | Gross hematuria | NA | LFT | Fluid collection and morphological change, Flank mass | Calcification and widened mediastinum, Filling defects in barium contrast | Metastasis and staging, Cystic and solid masses, Lymph node, renal vein, and inferior vena cava involvement | Soft tissue invasion and staging | Malignant cystic lesions percutaneous cyst puncture | Renal cell carcinoma types: Clear cell (75%), Chromophilic (15%), Chromophobic (5%), Oncocytoma (3%), Collecting duct (2%) | |
| Congenital kidney disease
– Agenesis |
± | – | – | – | ± | ± | – | – | ± | ↑HCT | ↓GFR | ↓P, ↓Ca | Microalbuminuria, Uricosuria | NA | Genetic testing forADPKD2 | Visualization of kidney cysts | Small kidney cysts (0.5 cm) | Kidney size, Intracranial aneurysms | NA | – | – | |
| End stage renal disease | + | – | – | – | ± | – | – | – | + | Anemia | ↓GFR, ↑BUN, ↑Cr | ↑K | Hypoalbuminuria | ↓HCO3 | Phosphate, 25–hydroxy vitamin D, Alkaline phosphatase, Parathyroid hormone | Hydronephrosis, Retroperitoneal fibrosis, Enlarged or shrunken kidneys | Renal masses, stones, and cysts | Renal vein thrombosis, Renal artery stenosis in magnetic resonance angiography | Percutaneous renal biopsy | – | ||
| Endogenous toxins | ± | – | ± | + | – | ± | – | – | ± | Anemia, Thrombocytopenia | ↓GFR, ↑BUN, ↑Cr | ↑K, ↑Urate, ↓Ca | Uricosuria, Hematuria, Myoglobinuria, Casts | NA | Creatine kinase > 1000 U/L | Malignant or cystic lesions, Hydronephrosis, Nephrocalcinosis, Urolithiasis | NA | Urolithiasis, Wilms tumor, Polycystic kidney disease | NA | Ureter or bladder abnormality in voiding cystourethrography | – | |
| Glomerulonephritis | ± | – | – | – | – | – | – | – | + | Pleocytosis, Anemia, Leukocytosis, ↑ESR | ↑BUN, ↑Cr | NA | Specific gravity > 1.020, Proteinuria, Hematuria, Red blood cell casts, White blood cell casts, Cellular casts, Oval fat bodies | NA | NA | ↑C3, ↑C4, ↑CH50, Blood and tissue culture, Antinuclear antibodies, Cryoglobulins,Hepatitis B and C serologies, Antineutrophil cytoplasmic antibody (ANCA) | Kidney size, Echogenicity of the renal cortex, Obstruction, Degree of fibrosis | Pulmonary congestion | Visceral abscesses | – | Renal biopsy, Light and electron microscopy, Immunofluorescence aid diagnosis | |
| Goodpasture syndrome | ± | – | – | – | – | – | – | ± | ± | Anemia, Leukocytosis, ↑ESR | ↑BUN, ↑Cr | NA | Low–grade proteinuria, Gross or microscopic hematuria, RBC casts | NA | Anti– glomerular basement membrane antibody Antineutrophilic cytoplasmic antibody | NA | Bilateral, basal, patchy parenchymal consolidations | NA | NA | Diffuse alveolar hemorrhage in pulmonary biopsy | – | |
| Hemolytic uremic syndrome | ± | – | ± | ± | ± | + | + | – | ± | Severe anemia, Thrombocytopenia, ↑ aPTT | ↑BUN, ↑Cr | NA | Mild proteinuria, Red blood cells, Red blood cell casts | NA | Schistocytes, ↑FDP and D–dimer, ↑ Bilirubin, ↑LDH, ↓Haptoglobin, Stool culture (for E coli 0157:H7 or shigella), ↓ADAMTS–13 activity | Ruling out obstruction | NA | NA | NA | Diffuse thickening of the glomerular capillary wall, Swelling of endothelial cells, Fibrin thrombi in renal biopsy | – | |
| Nephrolithiasis | – | – | – | – | ± | ± | – | – | – | Mild leukocytosis, ↑CRP | ↑BUN, ↑Cr | ↑Na, ↑K, ↑P, ↑Ca, ↑Urate | Gross or microscopic hematuria, Red blood cells, Urinary crystals of calcium oxalate, uric acid, or cystine, Hypercalciuria, Urinary pH > 7 in struvite stones (Proteus, Pseudomonas, Klebsiella), Urinary pH < 5 in uric acid stones | ↓HCO3, Renal tubular acidosis | – | All types of stones are visible, Hydronephrosis, Abdominal aortic aneurysm, Cholelithiasis | Calcium – containing stones, Uric acid or cystine stones, Stone movement | Stone density, size and composition, Hydronephrosis, Nephromegaly, Perinephric fat streaking | NA | Intravenous pyelography (IVP), Renal tomography, Nuclear renal scan | – | |