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History
Presenting features
Fever with rash profile
Timeline of fever relative to rash
Rash evolution
Rash distribution
Rash symptoms
Pruritus
Pain
Burning
Mucosal symptoms
Oral lesions
Conjunctivitis
Exposures and context
Sick contacts
Daycare or school exposure
Animal exposure
Tick exposure
OPQRST
Onset
First fever time
First rash time
Provocation and palliation
Heat or sweat trigger
Sun exposure trigger
Relief with antihistamine
Quality
Maculopapular
Urticarial
Vesicular
Petechial or purpuric
Region and radiation
Trunk predominant
Acral predominant
Palms and soles involvement
Severity
Functional limitation
Sleep disruption
Timing
Continuous versus intermittent fever
Rash waxing and waning
Associated symptoms
Systemic symptoms
Rigors
Myalgias
Fatigue
Respiratory symptoms
Cough
Coryza
Sore throat
GI symptoms
Nausea
Vomiting
Diarrhea
Abdominal pain
Neuro symptoms
Headache
Neck stiffness
Photophobia
GU symptoms
Dysuria
Genital ulcers
Alarm Features
Immediate escalation triggers
High risk physiology
Systolic BP < 90 mmHg
MAP < 65 mmHg
HR > 130
RR > 30
SpO2 < 92 percent
Lactate >= 4 mmol/L
High risk appearance
Altered mental status
Severe lethargy
Toxic appearance
High risk rash patterns
Petechiae or purpura
Non blanching rash
Rapidly progressive rash
Skin necrosis
High risk mucocutaneous findings
Mucosal erosions
Conjunctival injection with pain
Facial edema
Cannot miss syndromes
Meningococcemia
Fever with petechiae or purpura
Shock or rapidly worsening status
Toxic shock syndrome
Hypotension with diffuse erythroderma
Multisystem involvement
Stevens Johnson syndrome or TEN
Painful rash
Mucosal involvement
Rocky Mountain spotted fever
Fever with headache
Tick exposure
Palms and soles involvement
Neutropenic sepsis with rash
Immunocompromised state
ANC low or expected low
Medications
Medication exposures
Current medications
Antibiotics within 1 to 3 weeks
Anticonvulsants
Allopurinol
NSAIDs
Immune checkpoint inhibitors
OTC and supplements
Acetaminophen
Herbal products
Recent changes
New medication within 8 weeks
Dose escalation within 8 weeks
High risk adverse drug syndromes
DRESS
New drug within 2 to 8 weeks
Facial edema
Eosinophilia
Serum sickness like reaction
Fever
Urticarial rash
Arthralgias
SJS or TEN triggers
Sulfonamides
Anticonvulsants
NSAIDs
Diet
Intake and hydration
Hydration status
Poor oral intake
Reduced urine output
Trigger exposures
New foods
Food additives
Caffeine and stimulants
Energy drinks
High caffeine intake
Travel food and water risk
Enteric exposure
Undercooked foods
Unfiltered water
Outbreak context
Recent cruise travel
Recent resort travel
Review of Systems
Skin and mucosa
Rash features
Blanching versus non blanching
Vesicles or bullae
Target lesions
Desquamation
Mucosal involvement
Oral ulcers
Genital ulcers
Eye redness
Infectious and systemic
Constitutional
Chills
Night sweats
Weight loss
Arthralgia and arthritis
Migratory joint pain
Swollen joints
Cardiorespiratory
Chest pain
Dyspnea
Palpitations
Neurologic
CNS symptoms
Headache
Neck stiffness
Confusion
Peripheral symptoms
Weakness
Paresthesias
Collateral History and Family History
Collateral and reliability
Source
Family report
Caregiver report
Reliability
Time course consistency
Medication list completeness
Family history
Inherited and autoimmune
Systemic lupus erythematosus (M32.9)
Inflammatory bowel disease
Primary immunodeficiency
Atopy
Eczema
Asthma
Drug allergies
Risk Factors
Host risk
Immunocompromise
HIV risk
Chemotherapy
Chronic steroids
Pregnancy and postpartum
Pregnancy status
Postpartum within 6 weeks
Pediatrics
Age under 3 months
Incomplete immunizations
Exposure risk
Travel
Endemic region travel
Recent international flight
Vector exposure
Tick exposure
Mosquito exposure
Sexual exposure
New partners
Condomless sex
Healthcare and device risk
Intravascular and skin portals
Recent IV line
Dialysis access
Skin breaks
Recent antibiotics
Risk of drug eruption
Risk of C difficile infection
Differential Diagnosis
Life threatening
Sepsis with petechiae or purpura
Meningococcemia (A39.2)
Pneumococcal sepsis with purpura
Toxic shock syndrome
Staphylococcal
Streptococcal
SJS or TEN (L51.1)
Mucosal involvement
Skin pain out of proportion
Necrotizing soft tissue infection (M72.6)
Severe pain
Bullae
Crepitus
RMSF and severe rickettsiosis (A77.0)
Severe headache
Thrombocytopenia
Disseminated varicella zoster
Immunocompromised
Multidermatomal vesicles
Common
Viral exanthem
Enterovirus
Parvovirus B19
Adenovirus
Urticaria with viral illness
Transient wheals
Migratory lesions
Cellulitis or erysipelas with fever (L03.90)
Localized warmth
Tenderness
Scarlet fever
Pharyngitis
Sandpaper rash
Drug eruption
Morbilliform rash
New medication exposure
Less common
Acute HIV seroconversion (Z21)
Fever with rash
Pharyngitis
Lymphadenopathy
Secondary syphilis (A51.9)
Palms and soles rash
Generalized lymphadenopathy
Measles
Cough
Coryza
Conjunctivitis
Varicella
Lesions in different stages
Pruritus
EBV or CMV mononucleosis
Exudative pharyngitis
Hepatosplenomegaly
Vasculitis
Palpable purpura
Hematuria
Endocarditis with embolic lesions (I33.0)
New murmur
Vascular phenomena
Key distinguishing clues
Petechial or purpuric rash
Meningococcemia prioritized
Thrombocytopenia prioritized
Palms and soles involvement
RMSF
Secondary syphilis
Hand foot mouth disease
Mucosal erosions
SJS or TEN
HSV
Vesicular rash
Varicella
Disseminated zoster
Target lesions
Erythema multiforme
Mycoplasma associated mucositis
Past Medical History
Conditions and baseline
Immune status
HIV status and last test
Splenectomy
Asplenia functional
Dermatologic history
Atopic dermatitis
Psoriasis (L40.9)
Autoimmune disease
Systemic lupus erythematosus (M32.9)
Rheumatoid arthritis (M06.9)
Recurrent infections
Prior invasive bacterial infection
Prior meningitis
Procedures and devices
Implanted or indwelling devices
Prosthetic valves
Vascular grafts
Recent procedures
Surgery within 30 days
Dental work
Physical Exam
General and vitals
Appearance and stability
Toxic appearance
Work of breathing
Perfusion
Vitals pattern
Persistent hypotension
Relative bradycardia
Fever magnitude and trend
Skin exam
Morphology and distribution
Macules and papules
Wheals
Vesicles
Bullae
Petechiae
Purpura
Blanching
Blanching lesions
Non blanching lesions
Tenderness and pain
Skin pain
Pain out of proportion
Special locations
Palms
Soles
Perineum
HEENT
Eyes
Conjunctival injection
Photophobia
Pain with eye movement
Mouth
Oral ulcers
Strawberry tongue
Pharyngeal exudate
Neck
Cervical lymphadenopathy
Meningismus
Cardiopulmonary
Heart
New murmur
Tachycardia out of proportion
Lungs
Crackles
Wheeze
Abdomen
Hepatosplenomegaly
Liver enlargement
Spleen enlargement
Peritonitis signs
Guarding
Rebound
Neurologic
Mental status
Orientation
Agitation
Focal deficits
Cranial nerves
Motor asymmetry
Lab Studies
Core ED labs
CBC with differential
Leukocytosis or leukopenia
Thrombocytopenia
CMP
AST and ALT elevation
Creatinine elevation
Lactate
Sepsis risk stratification
Trend after fluids
CRP and ESR
Inflammatory support
Baseline for trend
Infectious evaluation
Blood cultures
Two sets before antibiotics if feasible
Do not delay antibiotics in shock
Urinalysis and urine culture
GU source screen
Hematuria for vasculitis
Respiratory viral testing local protocol dependent
Influenza
SARS CoV 2
Syndrome targeted labs
Suspected RMSF or rickettsial illness
Platelets trend
Sodium trend
Suspected DRESS
Eosinophils
Hepatic enzymes
Suspected SJS or TEN
Electrolytes
Bicarbonate
Suspected meningitis
Coagulation studies
Type and screen
Pregnancy and sexual health
Pregnancy test
All patients with pregnancy potential
Ectopic red flags if positive
HIV testing
Fourth generation Ag Ab
HIV RNA if early suspicion
Syphilis testing
RPR or VDRL
Treponemal confirmatory test
Imaging
Scoring Systems
Sepsis screening tools local protocol dependent
qSOFA
SIRS criteria
SJS or TEN severity tools
SCORTEN
Limitations
Requires admission labs
Not validated for triage alone
MRI
CNS infection concern
Encephalitis concern with focal deficits
Persistent altered mental status
Soft tissue infection concern
Deep infection delineation
Osteomyelitis concern
CT
Head CT
Altered mental status
Focal neurologic deficits
Chest CT angiography
Alternative diagnosis when severe hypoxemia
Pulmonary embolism concern
Abdomen pelvis CT
Severe abdominal pain
Concern for intraabdominal source
Ultrasound
POCUS hemodynamics
IVC assessment context dependent
Cardiac function screen
Soft tissue POCUS
Abscess versus cellulitis
Subcutaneous gas concern
RUQ ultrasound
Hepatobiliary source concern
RUQ tenderness
Special Tests
Lumbar puncture pathway
Indications
Suspected meningitis
Suspected encephalitis
Pre LP safety
CT head triggers
Coagulopathy and anticoagulant status
CSF studies
Cell count and differential
Glucose
Protein
Gram stain and culture
Meningitis encephalitis PCR panel local protocol dependent
Dermatologic bedside tests
Nikolsky sign
SJS or TEN support
Not definitive alone
Diascopy
Blanching assessment
Purpura confirmation
Skin scraping when indicated
Scabies concern
Dermatophyte concern
Microbiology lesion testing
Vesicular lesion PCR
HSV
VZV
Throat testing
Rapid strep local protocol dependent
Throat culture when needed
ECG
Indications and high risk patterns
Indications
Chest pain
Dyspnea
Shock
High risk findings
ST elevation
New left bundle branch block
Ventricular tachycardia
Sepsis related patterns
Sinus tachycardia
QT prolongation risk with medications
Serial ECG logic
Ongoing symptoms
Repeat within 15 to 30 minutes
Repeat after clinical change
QT monitoring
QT prolonging antimicrobials
Electrolyte abnormalities
Assessment
Problem representation
Fever with rash syndrome
Rash pattern category
Maculopapular
Urticarial
Vesicular
Petechial or purpuric
Severity category
Stable without organ dysfunction
Suspected sepsis
Suspected mucocutaneous emergency
Working diagnoses to prioritize
Non blanching rash with fever
Meningococcemia prioritized
Sepsis bundle triggers
Painful rash with mucosal involvement
SJS or TEN prioritized
Burn or ICU capable center pathway
Tick exposure with systemic symptoms
RMSF or rickettsiosis prioritized
Doxycycline time sensitive
Diagnostic uncertainty and alternatives
Viral exanthem versus drug eruption
Medication timing support
Systemic toxicity argues against benign
Vasculitis versus thrombocytopenia
Palpable purpura support vasculitis
Platelet count guides pathway
Plan
First 5 minutes
Stabilization and monitoring
Airway assessment and oxygen if SpO2 < 92 percent
Cardiac monitor for unstable vitals
Two large bore IV if shock concern
Sepsis actions when indicated
Lactate within 1 hour
Blood cultures before antibiotics if feasible
Broad spectrum antibiotics within 1 hour for shock
Isolation actions when indicated
Droplet precautions for suspected meningococcemia
Airborne precautions for suspected measles or varicella
Diagnostic sequencing
Pattern based workup
Non blanching rash pathway
Vesicular rash pathway
Mucosal emergency pathway
Reassessment loop
Vitals every 15 to 30 minutes if unstable
Rash progression checks
Mental status checks
Therapeutics
Fluids for shock
Balanced crystalloid 30 mL per kg for septic shock
Reassess after each 500 to 1000 mL bolus
Empiric antibiotics for meningococcemia concern
Ceftriaxone IV 2 g
Repeat dosing per local protocol dependent
Empiric doxycycline for suspected RMSF
Doxycycline PO or IV 100 mg
Frequency every 12 hours
Anaphylaxis or severe urticaria
Epinephrine IM 0.3 mg
Repeat every 5 to 15 minutes if needed
Cetirizine PO 10 mg
SJS or TEN immediate actions
Stop suspected culprit drugs
Aggressive pain control
Early transfer to burn capable center when extensive
Consultation
Dermatology
Suspected SJS or TEN
Unclear severe rash diagnosis
Infectious diseases
Immunocompromised host
Suspected unusual travel related infection
ICU or critical care
Vasopressor requirement
Rapid deterioration
Disposition
ICU criteria
Shock
Vasopressor requirement
Lactate >= 4 mmol/L after fluids
Severe mucocutaneous disease
SJS or TEN concern
Extensive skin detachment
CNS infection concern
Altered mental status
Seizure
Inpatient admission criteria
Suspected invasive bacterial infection
Non blanching rash with fever
Positive blood cultures
Immunocompromised host
Neutropenia
High risk comorbidities
Organ dysfunction
AKI
Hepatitis
Hypoxemia
Observation or discharge criteria
Observation candidates
Uncertain diagnosis with stable vitals
Need serial reassessment
Discharge criteria
Hemodynamic stability
No mucosal involvement
No non blanching rash
Reliable follow up within 24 to 48 hours
Discharge Instructions
Copy discharge instructions
Summary
You were seen for fever with a skin rash
Your exam and tests today did not show an emergency cause
Medications
Take medications as prescribed
Avoid starting new medications unless advised
Hydration and activity
Drink fluids to keep urine light yellow
Rest until fever improves
Follow up
Primary care within 24 to 48 hours
Dermatology follow up if rash persists or worsens
Return to ER now if
Trouble breathing
New confusion
Fainting
Severe headache or neck stiffness
Rash that is purple or does not fade when pressed
Blistering rash
Mouth or eye sores
Severe pain
Signs of dehydration
References
Guidelines and key sources
Infectious Diseases Society of America
Practice guidelines for the diagnosis and management of skin and soft tissue infections 2014
Includes severe infection and necrotizing infection guidance
Centers for Disease Control and Prevention
Rocky Mountain spotted fever clinical guidance
Emphasizes early doxycycline treatment
Centers for Disease Control and Prevention
Meningococcal disease clinical information for healthcare providers
Supports immediate empiric therapy with compatible presentation
American Academy of Dermatology
Stevens Johnson syndrome and toxic epidermal necrolysis guidance
Emphasizes culprit drug discontinuation and supportive care
Surviving Sepsis Campaign
International guidelines for management of sepsis and septic shock 2021
Time sensitive bundle principles
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.