Practice Clinical Cases

Patient: 45-year-old female presents with fever, sore throat, and fatigue for the past week.

Medical History: She was started on methimazole for hyperthyroidism 2 months ago. No other significant medical history.

Physical Examination: Temperature 38.9C, oral examination shows pharyngeal erythema but no exudates, no lymphadenopathy, mild tachycardia, otherwise unremarkable.

Laboratory Results: WBC 0.810^9/L (neutrophils 0.210^9/L), hemoglobin 12.5 g/dL, platelets 21010^9/L.

Clinical Reasoning:

• Suspected Diagnosis: Drug-induced agranulocytosis, likely from methimazole.
• Key Clinical Finding: Severe neutropenia (agranulocytosis) in a patient recently started on an antithyroid drug.
• Diagnostic Approach: Evaluate for other causes of neutropenia (viral infections, autoimmune disorders, nutritional deficiencies) but prioritize stopping the suspected medication.
• Management: Immediately discontinue methimazole, hospitalize for close monitoring and administration of broad-spectrum antibiotics, consider granulocyte colony-stimulating factor (G-CSF) in severe cases, and switch to alternative therapy for hyperthyroidism after recovery.

Patient: 72-year-old male reports multiple episodes of hematuria and easy bruising over the past three days.

Medical History: Atrial fibrillation on warfarin for 18 months, chronic kidney disease (stage 3), recently started on a herbal supplement for joint pain.

Medications: Warfarin 5mg daily, lisinopril 10mg daily, omeprazole 20mg daily, recently started Ginkgo biloba supplement.

Physical Examination: Multiple ecchymoses on arms and legs, no other focal bleeding sites, BP 130/78 mmHg, HR 72 bpm, regular.

Laboratory Results: INR 6.8 (target 2.0-3.0), hemoglobin 10.2 g/dL (baseline 12.1 g/dL).

Clinical Reasoning:

• Suspected Diagnosis: Warfarin toxicity/over-anticoaguation.
• Contributing Factors: Recently started Ginkgo biloba supplement (known to enhance anticoagulant effect), CKD may affect warfarin metabolism.
• Management: Immediately hold warfarin, administer vitamin K 2.5-5mg orally (or IV if severe bleeding), consider fresh frozen plasma or prothrombin complex concentrate if life-threatening bleeding, review all medications and supplements for interactions, resume warfarin at reduced dose once INR is therapeutic, provide patient education about anticoagulant safety and supplement interactions.

Patient: 34-year-old female presents with fatigue, pallor, and occasional lightheadedness over the past two months.

Medical History: Menstrual periods are heavy, lasting 7 days with large clots. No other significant medical history.

Physical Examination: Pale conjunctiva, heart rate 88 BPM, blood pressure 110/70 mmHg, no hepatosplenomegaly.

Laboratory Results: Hemoglobin 9.2 g/dL, MCV 72 fL, ferritin 8 ng/mL, iron 30 g/dL, TIBC 450 g/dL, transferrin saturation 6.7%.

Clinical Reasoning:

• Suspected Diagnosis: Iron deficiency anemia.
• Key Findings: Microcytic anemia (low MCV) with low ferritin, iron, and transferrin saturation are characteristic of iron deficiency.
• Diagnostic Approach: Identify underlying causemenorrhagia in this case.
• Management: Oral iron therapy (ferrous sulfate 325mg or elemental iron 50-100mg daily), address underlying causeconsider hormonal therapy or NSAIDs for menorrhagia, patient education about dietary iron sources and absorption enhancers/inhibitors, follow-up in 4 weeks to assess hemoglobin response.

Patient: 24-year-old with known sickle cell disease presents with severe pain in both legs and lower back for the past 24 hours.

Medical History: Diagnosed with sickle cell anemia (HbSS) at 6 months, previous hospitalizations for pain crises, currently on hydroxyurea.

Current Medications: Hydroxyurea 15 mg/kg/day, folic acid 1mg daily.

Physical Examination: Pain score 9/10, appears uncomfortable, vital signs: T 38.0C, HR 110 bpm, BP 125/75 mmHg, mild tenderness in legs and lower back, no focal neurologic deficits, chest clear to auscultation.

Laboratory Results: Hemoglobin 8.5 g/dL (baseline 9.0 g/dL), WBC 12.510^9/L, reticulocyte count 8.5%, creatinine 0.9 mg/dL, total bilirubin 2.5 mg/dL (direct 0.5 mg/dL).

Clinical Reasoning:

• Suspected Diagnosis: Sickle cell vaso-occlusive crisis (acute pain).
• Key Findings: History of sickle cell disease, characteristic pain, mild leukocytosis, and elevated reticulocyte count.
• Diagnostic Approach: Rule out acute chest syndrome and infection as precipitating factors.
• Management: Aggressive pain control with opioids (patient-controlled analgesia preferred), IV fluids for hydration, oxygen if hypoxic, treat any precipitating infection if identified, monitor for acute chest syndrome and other complications, consider exchange transfusion in severe cases.

Patient: 68-year-old male presents with productive cough, fever, and shortness of breath for 3 days.

Medical History: Hypertension, type 2 diabetes mellitus, former smoker (30 pack-years), received influenza and pneumococcal vaccines 2 years ago.

Physical Examination: Temperature 38.8C, BP 135/85 mmHg, HR 105 bpm, RR 24/min, SpO2 92% on room air, decreased breath sounds and crackles in right lower lung field.

Diagnostic Studies: CXR shows right lower lobe consolidation; WBC 13.510^9/L with left shift.

Clinical Reasoning:

• Suspected Diagnosis: Community-acquired pneumonia (CAP).
• Risk Assessment: CURB-65 score of 2 (Confusion absent, Urea normal, RR24, BP normal, Age65), indicating moderate severity requiring hospital observation.
• Diagnostic Approach: Additional evaluation may include blood cultures, sputum Gram stain and culture, and urinary antigen tests for Streptococcus pneumoniae and Legionella.
• Management: Start appropriate antibiotic therapy (e.g., ceftriaxone plus azithromycin or respiratory fluoroquinolone), oxygen supplementation as needed to maintain SpO2 > 92%, adequate hydration and antipyretics for comfort, monitoring response to therapy over 48-72 hours, consider smoking cessation counseling.

Patient: 52-year-old male presents with rapidly spreading redness, swelling, and severe pain in the right lower leg over the past 12 hours.

Medical History: Type 2 diabetes mellitus, obesity (BMI 34), hypertension.

Physical Examination: Temperature 39.2C, BP 140/90 mmHg, HR 110 bpm, RR 20/min. Right lower leg shows extensive erythema extending from ankle to mid-calf, with edema, warmth, and extreme tenderness beyond the visible borders of erythema. No crepitus on palpation. Patient reports pain out of proportion to examination findings.

Laboratory Results: WBC 16.810^9/L with left shift, CRP 12 mg/dL, serum glucose 240 mg/dL, creatinine 1.2 mg/dL (baseline 0.9 mg/dL).

Clinical Reasoning:

• Suspected Diagnosis: Necrotizing soft tissue infection (likely necrotizing fasciitis) rather than simple cellulitis.
• Distinguishing Features: Pain out of proportion to visible findings, rapid progression, significant systemic toxicity.
• Diagnostic Approach: Immediate surgical consultation for potential incisional biopsy; MRI or CT can help determine extent of infection but should not delay surgical intervention.
• Management: Emergent surgical exploration and debridement, broad-spectrum IV antibiotics (e.g., vancomycin plus piperacillin-tazobactam or carbapenem), aggressive fluid resuscitation for sepsis, close monitoring in ICU setting, control of blood glucose.