Diagnosis

Erysipelas

Etiology

Cause [id6]

• Streptococcus pyogenes (group A streptococci, most common)

• Non–group A Streptococcus

• Staphylococcus

• Gram-negative species.

Pathophysiology [id6]

1. Skin trauma (insect bites, surgical incision, venous stasis ulcerations, IV drugs)

2. Breach of protective skin

3. Bacterial inoculation

4. Inflammation

Risk factors [id6]

• Immunosuppression: diabetes, alcohol abuse, HIV infection, nephrotic syndrome

• Lymphatic edema

• Lymphatic obstruction

• Excising the saphenous vein for bypass

• Arteriovenous fistula

• Status post-surgery

• Nephrotic syndrome

Complications [id6]

• Abscess

• Blisters

• Skin necrosis

• Scarlet fever

• Pneumonia

• Meningitis

• Hemorrhagic purpura

• Thrombophlebitis

• Toxic shock syndrome

• Necrotizing fasciitis

• Joint involvement

• Pyomyositis

• Clostridial myonecrosis (gas gangrene)

• Deep venous thrombosis

• Compartment syndrome

Epidemiology

Incidence per 100.000 [2rn]

Approach

• Blood test

• Culture

• Biopsy

Treatment

1. Symptomatic care: [w5w][szf]

   • Fever

   • Hydration

   • Cold compresses

   • Elevation to reduce local swelling, inflammation, and pain

2. Oral antibiotic treatment in the outpatient setting:

   • Penicillin V 500 mg x 4

   • Amoxicillin 875 mg x 2

   • Cephalexin 500 mg x 4

   • Cefadroxil 500 mg x 2

3. Parenteral antibiotics:

   • Systemic signs of toxicity: fever >38°C, hypotension, or tachycardia

   • Rapid progression of erythema (eg, doubling of the affected area within 24 hours)

   • Extensive erythema

   • High-risk neutropenia

   • Lymphangitis

   • Immunocompromised patients

   • Inability to tolerate or absorb oral therapy

4. Surgery: Debridement if necrosis or gangrene

Differential diagnoses

Angioedema, Cellulitis, Compartment syndrome, Contact dermatitis, Deep venous thrombosis, Eczema, Erysipeloid, Erythema induratum, Erythema nodosum, Familial mediterranean fever, Gout, Granuloma faciale, Herpes zoster, Impetigo, Lyme disease, Necrotizing fasciitis, Scarlet fever, Septic arthritis, Septic bursitis, Staphylococcal scalded skin syndrome, Systemic lupus erythematosus, Tenosynovitis, Toxic shock syndrome