Differential Diagnosis for Right Iliac Fossa Pain in an Obese Woman
The patient's presentation of right iliac fossa pain, anorexia, nausea, vomiting, and leukocytosis suggests an acute abdominal condition. Given the clinical scenario, the differential diagnoses can be categorized as follows:
Single Most Likely Diagnosis
- Acute Appendicitis: This is the most common cause of acute abdomen requiring surgical intervention. The patient's symptoms of right iliac fossa pain, anorexia, nausea, vomiting, and leukocytosis are classic for appendicitis. Obesity can sometimes make the diagnosis challenging due to deeper location of the appendix and difficulty in palpation.
Other Likely Diagnoses
- Ovarian Cyst or Torsion: Given the patient's gender, ovarian pathology is a consideration. Symptoms can include acute pain, nausea, and vomiting. Leukocytosis may not always be present but can occur, especially if there's associated infection or necrosis.
- Intestinal Obstruction: This could present with abdominal pain, nausea, vomiting, and leukocytosis if there's an associated infection or ischemia. The obstruction could be due to various causes, including adhesions, hernias, or tumors.
- Diverticulitis: Although less common in younger patients, diverticulitis can occur and presents with left lower quadrant pain more often but can occasionally present on the right side, especially if the sigmoid colon is located more to the right.
Do Not Miss Diagnoses
- Ectopic Pregnancy: Although the patient's presentation does not strongly suggest pregnancy, ectopic pregnancy is a life-threatening condition that must be considered in any woman of childbearing age presenting with acute abdominal pain. A pregnancy test should be performed.
- Mesenteric Lymphadenitis: This condition can mimic appendicitis and is often seen in younger patients. It's usually self-limiting but can be severe.
- Perforated Visculitis or Ulcer: Conditions like perforated ulcers or vasculitis can present with acute abdomen and require immediate attention.
Rare Diagnoses
- Right Lower Lobe Pneumonia: Referred pain from a lower lobe pneumonia can occasionally mimic an acute abdomen.
- Ureteric Colic: While typically presenting with flank pain, ureteric colic can sometimes cause lower abdominal pain and should be considered, especially if there's a history of kidney stones.
- Inflammatory Bowel Disease (IBD) Flare: Conditions like Crohn's disease or ulcerative colitis can present with acute abdominal pain, although they usually have a more chronic course.
Given the clinical presentation and the need for a definitive diagnosis, especially with the patient being obese which might obscure physical examination findings, imaging is crucial. Among the options provided:
- CT (B) is highly sensitive and specific for diagnosing appendicitis and other causes of acute abdomen but involves radiation.
- US (C) is a good initial choice, especially in young women, as it's non-invasive and doesn't involve radiation, making it safer for potential pregnancy. It's also useful for evaluating ovarian pathology.
- Diagnostic Laparoscopy (D) can be both diagnostic and therapeutic, especially if the diagnosis is unclear after imaging, but it's more invasive.
Considering the need for an accurate diagnosis without delay and the potential risks and benefits of each option, CT (B) or US (C) would be appropriate initial steps, with Diagnostic Laparoscopy (D) considered if the diagnosis remains unclear or if the patient's condition warrants immediate surgical intervention. Open Surgery (A) would typically follow a definitive diagnosis, often guided by imaging or laparoscopy findings.