What antibiotic would you use to treat infections associated with Henoch-Schönlein Purpura (HSP)?

Antibiotic Treatment for Henoch-Schönlein Purpura (HSP)

For HSP patients with documented streptococcal infection, treat with penicillin V 500 mg four times daily for 10 days or amoxicillin 500 mg three times daily for 10 days; for penicillin-allergic patients, use azithromycin 500 mg once daily for 3 days. 1

When to Use Antibiotics in HSP

Antibiotics are indicated only when there is evidence of an active bacterial infection triggering or complicating HSP, not as routine treatment for the vasculitis itself. 2, 3

Identifying Infectious Triggers

• Streptococcal infection is the most common infectious trigger in HSP, identified in 17.08% of cases in a large cohort study 3
• Look for recent upper respiratory infection (present in most HSP cases), elevated antistreptolysin O titers, or positive throat cultures 2, 4
• Other documented infectious triggers include Mycoplasma pneumoniae (4.83% of cases), Helicobacter pylori (5.92%), and less commonly respiratory viruses 3, 4
• HSP typically follows the infectious trigger by 1-3 weeks 2

Specific Antibiotic Regimens

For Group A Streptococcal Infection (Most Common)

First-line options:

• Penicillin V 500 mg orally four times daily for 10 days 1
• Amoxicillin 500 mg orally three times daily for 10 days 1

For penicillin-allergic patients:

• Azithromycin 500 mg once daily for 3 days 1
• Clindamycin 300 mg four times daily for 10 days 1

For Mycoplasma pneumoniae

• Azithromycin 500 mg once daily for 3-5 days 1
• Doxycycline (in patients >8 years old) 1

Evidence Supporting Antibiotic Use

A study of 1,200 HSP children demonstrated that symptomatic treatment plus adjunctive anti-infectious agents significantly improved the remission rate of purpura in infectious cases (p<0.01). 3 This suggests that complete elimination of infectious triggers may help relieve cutaneous purpura. 3

Critical Clinical Pitfalls

• Do not use antibiotics routinely in all HSP cases - HSP spontaneously resolves in 94% of children and 89% of adults without antibiotics 2
• Antibiotics do not treat the vasculitis itself - they only address the infectious trigger when present 2, 3
• The primary treatment for HSP remains supportive care, with corticosteroids (prednisone 1-2 mg/kg daily for 2 weeks) reserved for severe abdominal pain, joint symptoms, or renal involvement 2
• Testing for infectious triggers should include antistreptolysin O titers, Mycoplasma antibodies, and consideration of throat culture if upper respiratory symptoms are present 3, 4

Duration and Monitoring

• Complete the full 10-day course for streptococcal infections to ensure eradication and prevent relapse 1
• HSP relapse/recurrence occurs in 10.25% of cases, with infection being the most frequent trigger regardless of clinical phenotype 3
• Monitor for resolution of purpura, which should improve within days to weeks if an infectious trigger is successfully treated 3