Overview

Definition:
-Recurrent pancreatitis in children is defined as two or more distinct episodes of acute pancreatitis, or a persistent state of chronic pancreatitis, in the absence of a clear acquired cause such as trauma, infection, or biliary disease
-Genetic factors play a significant role in a substantial proportion of these cases, often leading to hereditary pancreatitis syndromes.
Epidemiology:
-The incidence of recurrent acute pancreatitis in children is estimated to be 0.3-1.3 per 100,000 children per year
-A significant percentage, ranging from 10% to 50% depending on the study population and diagnostic criteria, have an identifiable genetic predisposition
-Familial clustering is common, underscoring the hereditary component.
Clinical Significance: Identifying a genetic cause is crucial for several reasons: it allows for accurate diagnosis and classification of pancreatitis subtypes, facilitates early detection and management of affected family members, informs prognosis, guides genetic counseling, and may influence long-term management strategies to prevent further episodes and complications like chronic pancreatitis or pancreatic cancer.

Clinical Presentation

Symptoms:
-Epigastric pain, often severe and radiating to the back
-Nausea and vomiting
-Fever
-Abdominal distension
-Jaundice may be present in cases of common bile duct involvement
-Older children may describe the pain as constant and worsening
-Younger children may present with irritability and poor feeding.
Signs:
-Tenderness in the epigastrium
-Guarding and rigidity of the abdominal muscles
-Tachycardia and hypotension can indicate severity
-Fever
-Signs of dehydration
-Cullen's sign or Grey Turner's sign are rare but indicative of severe hemorrhagic pancreatitis.
Diagnostic Criteria:
-Diagnosis of acute pancreatitis relies on the presence of at least two of the following three features: characteristic abdominal pain
-Serum amylase or lipase levels at least three times the upper limit of normal
-Characteristic findings of acute pancreatitis on cross-sectional imaging (CT or MRI)
-Recurrence is defined by multiple such episodes or development of chronic pancreatitis features.

Diagnostic Approach

History Taking:
-Detailed family history of pancreatitis or pancreatic diseases is paramount
-History of recent trauma, infections (viral, bacterial), medications (e.g., valproate, azathioprine), metabolic disorders, and biliary tract abnormalities
-Nutritional history and presence of congenital anomalies
-Characterize the pain: onset, duration, severity, radiation, aggravating, and relieving factors.
Physical Examination:
-Complete abdominal examination focusing on tenderness, distension, guarding, and rebound tenderness
-Assess hydration status and vital signs
-Examine for signs of jaundice or signs of retroperitoneal hemorrhage
-Assess for any dysmorphic features or stigmata of underlying systemic diseases.
Investigations:
-Serum amylase and lipase: elevated levels confirm pancreatic inflammation, with lipase being more specific and having a longer half-life
-Complete blood count: leukocytosis may be present
-Liver function tests: assess for cholestasis
-Electrolytes, calcium, and triglycerides: hypocalcemia and hypertriglyceridemia can be causes or consequences
-Imaging: Ultrasound to rule out gallstones
-Contrast-enhanced CT scan is the gold standard for diagnosing acute pancreatitis, assessing severity, and identifying complications
-MRI/MRCP is useful for evaluating the pancreatic ductal system and common bile duct, especially in recurrent cases or suspected chronic pancreatitis.
Differential Diagnosis:
-Other causes of acute abdominal pain in children: appendicitis
-Cholecystitis
-Peptic ulcer disease
-Mesenteric adenitis
-Bowel obstruction
-Diabetic ketoacidosis
-Hemolytic uremic syndrome
-Intussusception
-Gastoenteritis
-Vasculitis
-Pancreatic pseudocyst
-Pancreatic abscess.

Genetic Testing And Genes

Rationale For Testing:
-Genetic testing is indicated in children with idiopathic recurrent acute pancreatitis, especially if there is a family history of pancreatitis or if pancreatitis occurs at a young age
-It helps identify specific genetic syndromes and guides management and counseling.
Prss1 Mutations:
-Mutations in the *PRSS1* gene, encoding cationic trypsinogen, are the most common cause of hereditary pancreatitis (HP)
-These mutations lead to auto-activation of trypsinogen, causing premature and auto-digestion of the pancreas
-Autosomal dominant inheritance with high penetrance
-Examples: R122H, N29I
-Individuals with *PRSS1* mutations have a significantly increased risk of developing chronic pancreatitis and pancreatic cancer.
Spink1 Mutations:
-Mutations in the *SPINK1* gene (serine protease inhibitor Kazal type 1) are another significant cause, often associated with autosomal recessive or recessive with modifier inheritance patterns
-SPINK1 is a pancreatic secretory trypsin inhibitor that protects the pancreas from premature trypsin activation
-Heterozygous carriers are generally asymptomatic, but homozygous or compound heterozygous mutations can lead to pancreatitis
-This is often seen in recurrent acute pancreatitis of unknown etiology and in tropical calcific pancreatitis.
Cftr Mutations:
-Mutations in the *CFTR* (cystic fibrosis transmembrane conductance regulator) gene are primarily associated with cystic fibrosis (CF), but even in individuals without classic CF phenotype, certain *CFTR* mutations can predispose to pancreatic dysfunction, including pancreatitis
-Pancreatitis in CF patients can be acute, chronic, or present as DIOS (Distal Intestinal Obstruction Syndrome)
-Testing is considered in children with recurrent pancreatitis, especially if there are other subtle CF symptoms like recurrent sinopulmonary infections, male infertility, or reduced sweat chloride values
-Pancreatic involvement in CF can be diverse, ranging from pancreatic insufficiency to pancreatitis.
Other Genes:
-While *PRSS1*, *SPINK1*, and *CFTR* are the most commonly tested, other genes associated with pancreatitis include *CTRC*, *CASR*, *CCK-BR*, *LIPE*, and *CPA1*
-Testing for these may be considered in complex cases or if initial testing is negative.

Management

Initial Management:
-Aggressive fluid resuscitation with intravenous crystalloids (e.g., Lactated Ringer's solution) at 5-10 mL/kg/hour
-Pain control with intravenous analgesics (e.g., morphine, hydromorphone)
-Nasogastric decompression if significant vomiting or ileus
-Nutritional support: Initially NPO (nil per os), followed by jejunal feeding distal to the ligament of Treitz once pain and nausea subside
-Avoid oral intake until markers normalize and pain resolves.
Medical Management:
-Pain management is critical
-Opioids are typically used
-Antiemetics for nausea and vomiting
-Close monitoring of fluid balance and electrolytes
-Antibiotics are reserved for documented infection or severe pancreatitis with signs of organ failure.
Surgical Management:
-Surgery is generally not the primary treatment for acute pancreatitis
-Indications include complications such as infected necrosis, pseudocyst requiring drainage, or biliary obstruction
-ERCP (Endoscopic Retrograde Cholangiopancreatography) may be indicated for removal of bile duct stones causing pancreatitis
-Pancreatic necrosectomy is reserved for severe infected necrosis.
Supportive Care:
-Close monitoring of vital signs, urine output, and abdominal examination
-Serial assessment of laboratory markers (amylase, lipase, CRP)
-Management of complications like pseudocysts, abscesses, or organ failure
-Genetic counseling for affected families.

Complications

Early Complications:
-Systemic inflammatory response syndrome (SIRS)
-Organ failure (respiratory, renal, cardiovascular)
-Acute peripancreatic fluid collections
-Pancreatic necrosis (necrotizing pancreatitis)
-Hemorrhagic pancreatitis.
Late Complications:
-Chronic pancreatitis leading to exocrine and endocrine insufficiency (diabetes mellitus)
-Pancreatic pseudocysts
-Pancreatic fistulas
-Malnutrition
-Increased risk of pancreatic cancer in *PRSS1* carriers.
Prevention Strategies:
-For children with confirmed genetic mutations, preventing further episodes is key
-This involves avoiding known triggers such as alcohol, certain medications, and high-triglyceride states
-Close monitoring for signs of chronic pancreatitis and diabetes
-Prophylactic screening for pancreatic cancer in *PRSS1* carriers may be considered in adulthood based on family history and genetic counseling.

Prognosis

Factors Affecting Prognosis:
-Severity of initial attack
-Presence of complications
-Underlying genetic mutation (*PRSS1* mutations are associated with higher risk of chronic pancreatitis and cancer)
-Timeliness and adequacy of supportive care
-Age at onset.
Outcomes:
-Most children with acute pancreatitis recover fully
-However, recurrent episodes increase the risk of chronic pancreatitis, which can lead to significant long-term morbidity
-For individuals with *PRSS1* mutations, the prognosis includes a lifelong increased risk of pancreatic malignancy.
Follow Up:
-Children with recurrent pancreatitis, especially those with identified genetic mutations, require lifelong follow-up
-This includes regular clinical assessments, monitoring for endocrine (diabetes) and exocrine (malabsorption) dysfunction, and imaging to detect structural changes
-Genetic counseling for patients and families is essential.

Key Points

Exam Focus:
-Understand the role of PRSS1, SPINK1, and CFTR genes in pediatric recurrent pancreatitis
-Differentiate the inheritance patterns and clinical implications of mutations in these genes
-Recognize when to suspect hereditary pancreatitis and the indications for genetic testing.
Clinical Pearls:
-A strong family history of pancreatitis is a major red flag for hereditary pancreatitis
-Always consider CFTR mutations even in the absence of classic CF symptoms when evaluating pediatric recurrent pancreatitis
-Genetic counseling is an integral part of managing children with hereditary pancreatitis.
Common Mistakes:
-Attributing all recurrent pancreatitis to gallstones or trauma and neglecting genetic causes, especially in young children
-Underestimating the significance of CFTR mutations in non-classic CF patients presenting with pancreatitis
-Failing to involve genetic counselors early in the management of suspected hereditary pancreatitis.