Skin rash: Differential Diagnosis by Symptom Pattern

• •Fever pattern and inflammatory signs
• •Exposure history, travel risk, and host immunity
• •Organ-localized signs vs systemic sepsis pattern

• •Morphology and distribution of skin findings
• •Trigger/exposure timing and recurrence pattern
• •Systemic involvement (airway, hemodynamics, fever)

• •Character of pain and exertional trigger
• •Hemodynamic instability, pulse pattern, and blood pressure
• •ECG and cardiac biomarkers trend

• •Pain location and relation to meals
• •Stool pattern (watery, bloody, greasy) and vomiting profile
• •Associated systemic signs such as fever or jaundice

• •Sudden vs progressive neurologic deficit
• •Focal deficits, consciousness changes, and meningeal signs
• •Headache phenotype and trigger pattern

Immediate testing when red flags are present

• •Focused examination with baseline labs if symptoms persist
• •Escalate to urgent workup when red flags appear

Group-directed workup

• •CBC with differential
• •CRP / ESR
• •Targeted cultures or PCR
• •Lactate if sepsis concern
• •Focused skin exam
• •Allergy workup when indicated
• •Infection swab/culture when needed
• •Biopsy in atypical persistent lesions