Etiologies of Chronic Pancreatitis (progressive inflammatory changes in the pancreas that result in permanent structural damage and histologic fibrosis)

–Alcohol abuse (45 %) as well as cigarette use
-Recurrent acute pancreatitis
–Genetic (eg: CFTR, SPINK mutations)
-Chronic ductal obstruction
-Systemic diseases (eg: SLE, hyperparathyroidism, hypertriglyceridemia)
-Idiopathic
–AUTOIMMUNE–Can be Type 1 (part of IgG4 disease) vs. Type 2 (idiopathic duct-centric pancreatitis without systemic involvement or IgG4 +) 

Clinical manifestations of chronic pancreatitis

-Can be ASYMPTOMATIC
–Epigastric abdominal pain most common symptom however
–Pancreatic insufficiency (only after 90 % of pancreatic function lost) and manifests as steatorrhea and glucose intolerance/diabetes
-Remember that chronic pancreatitis puts you at increased risk for PANCREATIC CANCER

Lab/Imaging

-Amylase/Lipase usually NORMAL so not as helpful
–72 hour quantitative fecal fat (steatorrhea alone is non-specific!)
–Fecal elastase has high sensitivity and specificity for chronic pancreatitis
-KUB can show calcifications hinting towards chronic pancreatitis and MRCP/ultrasound can show pancreatic duct obstructions, dilations, strictures or fluid collections

Treatment

-Alcohol and smoking cessation!
-Creon supplementation, may also need fat-soluble (A,D,K,E) supplementation
-Analgesics for abdominal pain which is extremely hard to control. Minimize opioids but may be necessary for refractory pain.
-Specialized approaches include celiac nerve blocks, endoscopic surgery and surgical resection

IgG4 related disease

–Inflammatory and Fibrotic systemic condition where organs have tumefactive (swelling), IgG4 positive lymphoplasmacytic infiltrate with often elevated IgG4 serum levels but not always

Clinical manifestations of IgG4 related disease

–Pancreatic involvement (manifests as pancreatic mass which can mimic CANCER, recurrent pancreatitis, strictures etc.)
–Biliary involvement (biliary strictures leading to obstructive jaundice as well as sclerosing cholangitis)
-ANY organ can be affected (eg: thyroiditis, interstitial nephritis, salivary involvement) Diagnosis and Treatment

http://www.nature.com/nrrheum/journal/v10/n3/full/nrrheum.2013.183.html

Diagnosis
-Diagnosis is made with the HISORt criteria (need at least one criteria)-see below

–Treatment is with STEROIDS and may need immunomodulating therapy depending on clinical course.

Further reading

NEJM article on IgG4 related disease 

Syncope

-Defined as ABRUPT and TRANSIENT loss of conscious associated with loss of postural tone followed by complete and RAPID spontaneous recovery
-Before you start working up syncope, make sure it is not a mimic like a seizure!

How do you make the diagnosis?

-Keep in mind that the majority of syncopal episodes are of unknown etiology but the most common known etiology is neurocardiogenic or vasovagal syncope. Despite what you saw on that episode of Scrubs, this type of syncope is not diagnosed with a blood test
-A detailed H&P makes the diagnosis in about 50 % of patients with syncope, especially focusing on whether it was EXERTIONAL, Prodromal symptoms, changes in position during event, FAMILY HISTORY of sudden cardiac death, and any associated cardiac symptoms. 
–Check orthostatics and EKG on everyone (still low yield but minimal cost and EKG can help you look for more dangerous etiologies)
–Telemetry is reasonable and recommended if you suspect a cardiac etiology for the syncope based on the H&P and EKG

-Do NOT get brain imaging (CT/MRI) in simple syncope as the yield is extremely low unless high suspicion for intracranial mass 
-Echocardiogram and carotid ultrasound are also extremely low yield unless EKG or exam shows concerning features (eg: ejection murmur on exam concerning for AS, young male with severe LVH concerning for HOCM, bilateral carotid bruits)
-See below for common causes of syncope, diagnostic testing, and treatment (from Medscape)

What is the San Francisco Syncope Rule?

-One of the many prognostic rules to look at whether someone is at high risk for serious outcomes and may need to be admitted if they meet ANY of these criteria
-If they meet NONE of the criteria with no other obvious source of syncope (eg: melena on exam),  high NPV for serious outcomes from syncope at 7 or 30 days.

Conditions to look out for on an EKG of a young patient with Syncope

-HOCM
–Long QT syndrome (acquired or congenital) as increased risk of Torsades
-Brugada Syndrome
-Arrhythmogenic right ventricular dysplasia (ARVD)
-Arrhythmias
-Tachyarrhythmias (esp. VT but also WPW)
-Bradyarrhythmias (eg: heart block)

Workup of suspected LQTS

-Rule out secondary etiologies of prolonged Qtc (long list but includes many electrolyte abnormalities as well as DRUGS). BRADYCARDIA prolongs the QT interval.
-LQT1-LQT13 genetic testing as determining genotype can affect clinical course
-GXT testing to look for arrhythmias as well as monitor QT interval (normally decreases with increased HR but not always in LQTS)

Treatment

–Beta Blockers FIRST LINE but at higher risk for heart block
-Keep Mg and K at normal limits to avoid Qtc prolongation, avoid drugs that can worsen prolongation
-PPM, left cardiac sympathectomy, and AICD may be needed
-Referral to center with radiofrequency catheter ablation.

Glomerulonephritis (basic breakdown)

-Can be acute, chronic, or due to RPGN

1. Anti-GBM  disease 
2. Pauci-immune GN
   1. GPA
   2. EGPA
   3. MPA
3. Immune Complex GN
   1. Systemic involvement
      1. SLE
      2. Endocarditis
      3. Cryoglobulinemia
      4. HSP
   1. Isolated Renal
      1. IgA Nephropathy
      2. IRGA (Infection Related GN)
      3. MPGN

Clinical presentation of Glomerulonephritis

–Hematuria
–Dysmorphic RBC or RBC casts
-Sub-nephrotic range usually (but can be nephrotic range) proteinuria often with renal failure
-HTN
-Edema

How do you distinguish the etiology of an immune complex GN? 

                                      Check COMPLEMENT levels!

Diseases with LOW complement

1. SLE (low C3 and C4 and often + ANA Anti-dsDNA)
2. Cryoglobulinemia (Low C4 and C4, often associated with HCV with + Cryo)
3. Endocarditis (Low C3, RF for endocarditis, fever, + BC etc.)
4. IRGA (usually low C3, now always PSGN and Staph related GN is just as common now)-classic teaching is that PSGN occurs weeks after infection but can occur concurrently with infection with other etiologies such as Staph!)

Diseases with NORMAL complement

1. HSP (only systemic IC disease with normal complement)
2. IgA nephropathy (often compared to PSGN which has low complement and usually occurs weeks after infection later than with IgA nephropathy)

Lupus Nephritis

-Making the diagnosis of Lupus is commonly done using the SLICC criteria (see below).

-While not part of the criteria, SPLENOMEGALY can be seen with SLE like our patient and should make you suspect SLE!
-There are SIX classes of Lupus Nephritis and biopsy is important to guide therapy
-Nearly everyone with SLE requires a renal biopsy EXCEPT those with

1. Protein excretion <500 mg/day
2. Bland urine sediment (no dysmorphic RBC, RBC casts)
3. Normal creatinine

Classic Triad of Infectious Mono

-Fever
-Pharyngitis
-Lymphadenopathy

*Most common symptoms however are MALAISE and SORE THROAT. Less common but if you see Palatal Petechiae, think about Mono!

Epidemiology

-Most common in adolescents aged 10-19 but can be seen in adults as well

Etiology

-EBV (Epstein Barr Virus)-90-95 % people are EBV seropositive but long latency period.
-Spread by Saliva and sexual transmission (not just the kissing disease)

Diagnosis

-Heterophile antibodies (Monospot is using Horse RBC agglutination)
Sensitivity=85 % while Specificity=97-100 % (can be falsely negative up to 25 % in first week so VCA may be more helpful)
-VCA (Viral Capsid Antigen) IgG, IgM
-Peripheral smear may show >50 % lymphocytes with atypical lymphocytes (see below)

Signs and Symptoms 

–Presentation differs depends on whether young or old as those in older groups have more atypical presentations (see below) including neutropenia and severe infection like our patient had!

Differential Diagnosis

Always keep Acute HIV infection in mind if you are thinking Mono but also includes Strep pharyngitis, Acute CMV, Toxoplasmosis, and Viral Pharyngitis.

Treatment

-Supportive care, hydration, NSAIDs/APAP use PRN
-No benefit to support routine use of H2 blockers, Acyclovir, or steroids although Acyclovir can decrease shedding time of virus
-4 weeks no contact sports (due to very low risk of splenic rupture) but they do NOT need to be on bed rest.
-Avoid ampicillin/amoxicillin as can classically cause a morbilliform rash

Further reading

NEJM article on Infectious Mononucleosis