Trimethoprim component 8 to 12 mg per kg per day divided twice daily
Key cautions
Hyperkalemia risk
Renal dosing adjustment
Sulfonamide allergy
Doxycycline
Adult dosing
100 mg orally twice daily
Pediatric dosing
Avoid under 8 years in most cases
Key cautions
Photosensitivity
Pregnancy avoidance
Clindamycin
Adult dosing
300 to 450 mg orally three times daily
Pediatric dosing
10 to 13 mg per kg per dose orally three times daily
Key cautions
Diarrhea and C difficile risk
Local resistance variability
Streptococcal coverage when prominent cellulitis
Cephalexin
Adult dosing
500 mg orally four times daily
Pediatric dosing
25 to 50 mg per kg per day divided 3 to 4 times daily
Amoxicillin
Adult dosing
500 mg orally three times daily
Pediatric dosing
25 to 50 mg per kg per day divided 2 to 3 times daily
Combined strategy when both MRSA and streptococcal coverage needed
Trimethoprim sulfamethoxazole plus beta lactam
Trimethoprim sulfamethoxazole dosing as above
Cephalexin dosing as above
Doxycycline plus beta lactam
Doxycycline dosing as above
Cephalexin dosing as above
Clindamycin monotherapy option
Use when local MRSA susceptibility supports
C difficile risk context
Intravenous antibiotics for severe infection
Intravenous antibiotics for severe infection
MRSA coverage
Vancomycin
Initial dosing
15 to 20 mg per kg IV per dose
Typical interval every 8 to 12 hours
Monitoring
Trough or AUC guided strategy per local protocol
Renal function monitoring
Linezolid
Adult dosing
600 mg IV every 12 hours
Key cautions
Serotonergic drug interaction risk
Thrombocytopenia with prolonged use
Daptomycin
Adult dosing
4 mg per kg IV daily for complicated skin infection context
Key cautions
Creatine kinase monitoring
Avoid for pneumonia
Ceftaroline
Adult dosing
600 mg IV every 12 hours
Key cautions
Beta lactam allergy context
Broad spectrum coverage when polymicrobial risk or necrotizing infection concern
Piperacillin tazobactam
Adult dosing
4.5 g IV every 6 to 8 hours
Key cautions
Renal dosing adjustment
Cefepime plus metronidazole option
Cefepime
2 g IV every 8 to 12 hours
Metronidazole
500 mg IV every 8 hours
Add clindamycin for toxin suppression when necrotizing infection concern
Adult dosing
900 mg IV every 8 hours
Adjunctive care
Adjunctive care
Analgesia
Acetaminophen dosing per age and weight
NSAID use when no contraindication
Short course opioid only if severe pain and appropriate
Tetanus prophylaxis
Update based on immunization status and wound classification
MRSA decolonization for recurrent disease context
Intranasal mupirocin course consideration
Chlorhexidine body wash course consideration
Household hygiene measures
Wound follow up plan
Packing removal timing
Recheck timing 24 to 48 hours when high risk
Evidence levels and guideline style statements
Evidence levels and guideline style statements
Incision and drainage as primary therapy for uncomplicated cutaneous abscess
ACEP Level B recommendation
Adjunct antibiotics after drainage improve cure for some uncomplicated abscesses
ACEP Level B recommendation
Antibiotics indicated for abscess with systemic signs or extensive cellulitis
Class I recommendation
Ultrasound improves identification of drainable collections in equivocal exam
ACEP Level B recommendation
Necrotizing infection concern requires immediate surgical evaluation without imaging delay
Class I recommendation
Special Populations
Pregnancy
Pregnancy
Diagnostic considerations
Lower threshold for systemic evaluation when febrile
POCUS preferred when imaging needed
Antibiotic selection
Avoid doxycycline
Fetal tooth and bone effects concern
Trimethoprim sulfamethoxazole precautions
First trimester folate antagonism concern
Near term neonatal jaundice risk context
Preferred options when appropriate
Clindamycin when susceptible
Beta lactams for streptococcal coverage
Disposition considerations
Lower threshold admission with systemic features
Obstetric coordination when severe infection
Geriatric
Geriatric
Presentation differences
Blunted fever response
Atypical mental status changes
Medication considerations
Renal dosing adjustment need
Higher adverse effect risk
Disposition considerations
Lower threshold admission with frailty
Home wound care feasibility assessment
Pediatrics
Pediatrics
Procedure considerations
Topical anesthetic adjunct options
Sedation readiness for large painful lesions
Antibiotic dosing
Weight based dosing with max adult caps
Local MRSA susceptibility relevance
Return precautions emphasis
Worsening fever
Decreased intake
Lethargy
Disposition considerations
Lower threshold observation in infants with fever
Background
Epidemiology
Epidemiology
Common emergency presentation within skin and soft tissue infections
Community acquired MRSA as frequent pathogen in purulent infections
Recurrent disease common in household clusters
Anatomic patterns
Follicular origin common in furuncles
Axillary and groin clustering in hidradenitis
Complication risk groups
Diabetes mellitus
Immunocompromise
Peripheral vascular disease
Pathophysiology
Pathophysiology
Localized collection of pus in dermis or subcutaneous tissue
Neutrophil accumulation
Liquefaction necrosis
Surrounding cellulitis
Inflammatory edema and bacterial spread in dermis
Lymphangitic involvement possible
Progression pathways
Spontaneous drainage
Extension to deeper fascia or muscle in severe cases
Microbiology patterns
Staphylococcus aureus common in purulent abscess
Streptococci common in nonpurulent cellulitis component
Polymicrobial organisms in perineal and bite associated infections
Therapeutic Considerations
Therapeutic considerations
Source control as key determinant of cure
Antibiotics alone inadequate for many abscesses without drainage
Antibiotic benefit strongest in selected groups
Systemic signs
Extensive cellulitis
High risk hosts
Larger lesions
Resistance and stewardship
Local antibiogram relevance
Narrowing therapy after culture when available
Procedure choices impact comfort and follow up needs
Loop drainage may reduce packing related pain
Routine packing not always beneficial for small simple abscesses
Harm prevention
Avoid incision over critical neurovascular structures
Imaging guidance for deep or high risk locations
Patient Discharge Instructions
Copy discharge instructions
Copy discharge instructions
Wound care
Keep dressing clean and dry for first 24 hours
Daily gentle washing after 24 hours
Warm compresses 10 to 15 minutes several times daily
Drainage expectations
Continued mild drainage for 24 to 72 hours can be normal
Sudden increase in swelling or pain after initial improvement needs reassessment
Packing or loop care when used
Follow up for recheck and removal in 24 to 48 hours
Do not remove at home unless instructed
Medications
Complete prescribed antibiotic course if given
Take pain medications as directed
Return to emergency care now for red flags
Fever or chills
Rapidly spreading redness
Worsening pain
Red streaking up the limb
New numbness or weakness near the site
Persistent vomiting or inability to keep fluids down
Confusion or fainting
Black or purple skin change
Severe pain out of proportion
Follow up
Primary care or wound check in 24 to 48 hours if packing used or high risk
Earlier follow up if symptoms worsen
Prevention
Avoid sharing towels or razors
Cover draining wounds
Hand hygiene
Clean high touch surfaces during outbreaks in household
References
Clinical guidelines and key sources
Clinical guidelines and key sources
Infectious Diseases Society of America guideline for skin and soft tissue infections
Purulent infection management with incision and drainage as primary therapy
Antibiotic selection based on severity and MRSA risk
Emergency medicine clinical policy topics for skin and soft tissue infection evaluation
Ultrasound utility for abscess identification
Antibiotics role after drainage in selected patients
Surgical principles for necrotizing soft tissue infections
Early surgical exploration priority when suspected
Broad spectrum antibiotics plus MRSA coverage when suspected
Antimicrobial stewardship principles for outpatient SSTI
Use local antibiogram for empiric choices
Narrow therapy when culture results available
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.