A 28-year-old woman from Delhi presents with a 10-day history of sustained fever (39–40°C), headache, myalgia, and abdominal pain. She reports constipation initially, followed by loose stools. On examination, she has hepatosplenomegaly, rose spots on the trunk, and a relative bradycardia (pulse 88/min despite high fever). Blood culture on day 3 of illness grew Salmonella typhi. She was started on ceftriaxone. On day 5 of antibiotic therapy, she develops sudden severe abdominal pain, abdominal distension, and signs of peritonitis. Her abdomen is rigid with absent bowel sounds. What is the most likely complication?

Explanation

## Clinical Presentation of Enteric Perforation **Key Point:** Enteric perforation is a life-threatening complication of typhoid fever, typically occurring in the 3rd–4th week of untreated disease, but can occur even during appropriate antibiotic therapy if there is extensive mucosal necrosis. ### Pathophysiology 1. Salmonella typhi causes hyperplasia and necrosis of Peyer's patches in the terminal ileum 2. Ulceration penetrates the full thickness of the bowel wall 3. Perforation leads to acute peritonitis and sepsis 4. Risk is highest in the 2nd–3rd week; can occur during treatment if bacterial load is high ### Clinical Features of Perforation - **Sudden onset** of severe, colicky abdominal pain - **Rigid abdomen** with rebound tenderness and guarding - **Absent bowel sounds** (ileus) - **Signs of peritonitis** (fever, tachycardia, hypotension) - **Abdominal distension** from free air and fluid - Plain X-ray abdomen: **free air under diaphragm** (pneumoperitoneum) **High-Yield:** The combination of **sustained fever + rose spots + hepatosplenomegaly + sudden peritonitis during antibiotic therapy** is pathognomonic for typhoid with perforation. ### Why This Case Points to Perforation - **Timing:** Day 5 of antibiotics (bacterial load still high in Peyer's patches) - **Classic signs:** Rigid abdomen, absent bowel sounds, peritonitis - **Preceding typhoid:** Rose spots, hepatosplenomegaly, relative bradycardia are hallmarks - **Acute deterioration:** Sudden change in clinical course **Clinical Pearl:** Perforation occurs in 1–3% of typhoid cases; mortality is 20–30% even with surgery. Early surgical intervention (primary repair or resection) is life-saving. **Mnemonic: PERFORATION SIGNS** — **P**eritoneal rigidity, **E**rect X-ray (free air), **R**ebound tenderness, **F**ever + sepsis, **O**utput loss (absent bowel sounds), **R**ising WBC, **A**cute pain, **T**achycardia, **I**leus, **O**utcome: surgery, **N**ecrosis of Peyer's patches.