Microangiopathic Hemolytic Anemia (MAHA)

Laboratory Evaluation Anemia in the setting of increased reticulocyte count, elevated LDH, decreased haptoglobin, elevated plasma free hemoglobin, elevated indirect bilirubin, and a negative Coomb’s test (see Anemia) raises suspicion for a microangiopathic hemolytic anemia (MAHA). A peripheral smear may elicit schistocytes (see above picture). Initial workup in the suspicion for a microangiopathic hemolytic anemiaContinue reading “Microangiopathic Hemolytic Anemia (MAHA)”

Viral Hepatitis

Hepatitis A Virus (HAV) Transmission: Fecal-oral Presentation: Febrile illness, nausea/vomiting, diarrhea, anorexia, abdominal distension, rarely causes fulminant liver disease Diagnosis: Hepatitis A Virus IgM Management: Conservative management Hepatitis B Virus (HBV) Transmission: Blood, sex, vertical (mother-to-baby) Presentation Acute: Similarly to Hepatitis A: Febrile illness, nausea/vomiting, diarrhea, abdominal pain. Rarely, jaundice and fulminant liver disease. Chronic:Continue reading “Viral Hepatitis”


Coagulation Cascade Coagulation Labs PT (Prothrombin Time): Thromboplastin (which contains Tissue Factor) is added to blood and the time needed to clot is recorded. Specifically analyzes the extrinsic pathway (factors II, V, VII, and X, and fibrinogen) (1) INR (International Normalized Ratio): Because of variability in thromboplastin reagent mixtures around the world, the INR wasContinue reading “Coagulation”

Lumbar Puncture Interpretation

Meningitis Routine Laboratory Results Specific Markers PCR May vary from center to center, but generally will detect E. coli, H. influenzae, N. meningitidis, Listeria monocytogenes, Streptococcus agalactiae, Streptococcus pneumoniae, CMV, Enterovirus, HSV 1/2, HHV-6, Human parechovirus, VZV, and Cryptococcus neoformans/gattii ADA (Adenosine Deaminase) Sensitivity and specificity for tuberculous meningitis varies depending cutoff level, however, approachesContinue reading “Lumbar Puncture Interpretation”

Lactic Acidosis

Lactic acid is a commonly obtained laboratory marker. The differential diagnosis for a patient with a lactic acidosis is broad. Differentiating these etiologies requires an understanding of the underlying biochemical pathways. Type A (Hypoxic) Tissue Hypoxia This is the most common cause of lactic acidosis, especially in patients with shock When tissue is not receivingContinue reading “Lactic Acidosis”


The inner ear is composed of two separate departments: the cochlea (for hearing), and the vestibule (for balance/positioning). The vestibular system consists of three semicircular canals, all at 90 degrees from each other. The semicircular canals contain an outer, “osseous”, labyrinth and an inner, “membranous” labyrinth. Inbetween the two labyrinths lies endolymphatic fluid. These canalsContinue reading “Vertigo”


Definition: A systemic autoimmune disease characterized by the presence of noncaseating granulomatas. Most commonly affects the lungs, with potential additional involvement of the eyes, salivary glands, lungs, heart, liver, and spleen. Extrapulmonary disease in the absence of pulmonary involvement is rare (1) Eyes (2) Uveitis or episcleritis/scleritis Complications: glaucoma or cataracts Parotid Gland (3) GenerallyContinue reading “Sarcoidosis”

Secondary Hypertension

~10% of cases of hypertension are secondary to another disease process (1). Secondary hypertension should be evaluated in young patients with otherwise-unexplained hypertension or patients with difficult-to-control hypertension. The most common etiologies are: Hyperthyroidism Hyperaldosteronism Hypercalcemia Obstructive Sleep Apnea Renovascular Hypertension Chronic Kidney Disease Coarctation of the Aorta Cushing Syndrome PheoChromocytoma One mnemonic to rememberContinue reading “Secondary Hypertension”

Cushing Syndrome

Definitions Cushing syndrome: Elevated cortisol levels from any cause (exogenous or endogenous, ACTH-dependent or independent) Cushing disease: Hypercortisolism specifically due to an ACTH-secreting pituitary adenoma Signs/Symptoms Hypertension Hyperglycemia Abdominal striae Lipid re-distribution Central obesity “Moon” facies “Buffalo hump” on back of neck Fatigue/weakness Workup Management: Cushing’s Disease (ACTH-secreting pituitary adenoma) (1) 1st Line Surgical resectionContinue reading “Cushing Syndrome”

Tick-Borne Disease

Suspect tick-borne disease when a patient presents with a flu-like illness +/- a rash in a geographical location consistent with known tick-borne disease. Classically, patients will also present with transaminitis and thrombocytopenia. Diagnosis can be confirmed with serology, but often, the diagnosis can be made clinically and empiric treatment may need to be initiated beforeContinue reading “Tick-Borne Disease”