Fever With RashAPPROACH

INFECTIOUS DISEASE AND FEVER SYNDROMES · 19 SECTIONS

⚲

599 items

☷ Legend

⚲

Resuscitation and Universal Approaches9▾

Chest and Cardiovascular12▾

Respiratory11▾

Abdominal and Gastrointestinal24▾

Renal and Urinary7▾

Neurologic11▾

Back and Neck8▾

Women's Health, Pregnancy, and GU11▾

Infectious Disease and Fever Syndromes11▾

Fever In The Immunocompromised Patient Fever With Rash Animal Bites And Rabies Risk Assessment Tick Exposure And Tick Borne Illness Concern Sepsis Concern Without Clear Source Soft Tissue Infection Concern Abscess And Skin Infection Concern Sore Throat Sore Throat And Pharyngitis Symptoms Meningitis Envenomation And Bites

Allergy and Dermatology7▾

Musculoskeletal and Extremities14▾

Trauma and Wounds14▾

ENT, Eye, Dental10▾

Endocrine, Metabolic, and Abnormal Labs9▾

Toxicology and Behavioral14▾

Pediatrics16▾

Environmental and Exposure4▾

01History/hx58

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

02Alarm Features/alarm36

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

03Medications/meds24

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

04Diet/diet15

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

05Review of Systems/ros27

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

06Collateral History and Family History/chafh14

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

07Risk Factors/rf26

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

08Differential Diagnosis/ddx74

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

09Past Medical History/pmh19

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

10Physical Exam/exam54

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

11Lab Studies/labs42

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

12Imaging/img32

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

›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

13Special Tests/spec27

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

14ECG/ecg17

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

15Assessment/ax25

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

16Plan/plan45

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

17Disposition/dispo27

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

18Discharge Instructions/di22

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

19References/r15

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

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed February 24, 2026

SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.

Fever With RashAPPROACH

INFECTIOUS DISEASE AND FEVER SYNDROMES · 19 SECTIONS

⚲

599 items

☷ Legend

⚲

Resuscitation and Universal Approaches9▾

Chest and Cardiovascular12▾

Respiratory11▾

Abdominal and Gastrointestinal24▾

Renal and Urinary7▾

Neurologic11▾

Back and Neck8▾

Women's Health, Pregnancy, and GU11▾

Infectious Disease and Fever Syndromes11▾

Allergy and Dermatology7▾

Musculoskeletal and Extremities14▾

Trauma and Wounds14▾

ENT, Eye, Dental10▾

Endocrine, Metabolic, and Abnormal Labs9▾

Toxicology and Behavioral14▾

Pediatrics16▾

Environmental and Exposure4▾

01History/hx58

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

02Alarm Features/alarm36

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

03Medications/meds24

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

04Diet/diet15

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

05Review of Systems/ros27

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

06Collateral History and Family History/chafh14

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

07Risk Factors/rf26

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

08Differential Diagnosis/ddx74

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

09Past Medical History/pmh19

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

10Physical Exam/exam54

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

11Lab Studies/labs42

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

12Imaging/img32

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

›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

13Special Tests/spec27

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

14ECG/ecg17

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

15Assessment/ax25

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

16Plan/plan45

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

17Disposition/dispo27

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

18Discharge Instructions/di22

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

19References/r15

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

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed February 24, 2026

SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.