What is the treatment for ivy (toxicodendron) dermatitis?

Treatment of Ivy (Toxicodendron) Dermatitis

The most effective approach to treating poison ivy dermatitis is immediate washing of the exposed area with soap and water or a commercial decontamination product, followed by symptomatic management with cool compresses, oatmeal baths, and prescription-strength corticosteroids for moderate to severe cases. 1

Immediate Management After Exposure

1. Decontamination (highest priority):

   • Wash exposed areas with soap and water or commercial decontamination products immediately 1
   • Effectiveness of washing decreases rapidly with time:
     • 100% removal if done immediately
     • 50% at 10 minutes
     • 25% at 15 minutes
     • 10% at 30 minutes 1
   • Commercial decontamination products, hand cleaners, or dishwashing soap can reduce symptoms by 55-70% even when used up to 2 hours after exposure 1

2. Remove and wash all clothing that may have contacted the plant

Treatment of Established Dermatitis

Mild Cases (Grade 1)

• Cool compresses to affected areas 1
• Oatmeal baths for symptomatic relief 1
• Over-the-counter hydrocortisone (0.2-2.5%) - note that efficacy is limited 1, 2
  • Apply to affected area no more than 3-4 times daily 2
  • Not recommended for children under 2 years without medical supervision 2

Moderate to Severe Cases (Grades 2-3)

• Prescription-strength topical corticosteroids 1

  • Low-potency OTC corticosteroids have not shown significant symptom improvement 1
  • High-potency topical corticosteroids combined with systemic corticosteroids have been shown to reduce itching duration 1

• Systemic corticosteroids for widespread or severe reactions

  • Treatment should last at least 14 days 3
  • Shorter durations (1-13 days) are associated with increased risk of return visits 3

Additional Symptomatic Relief

• Antihistamines:
  • Limited evidence for effectiveness in reducing itching 1
  • May be helpful for sleep at night but questionable efficacy for daytime itching 1
  • One observational study of 89 participants found no statistically significant reduction in symptoms 1

Special Considerations

For Eyelid Involvement

• Use low-potency topical corticosteroids (1% hydrocortisone) for short periods (less than 8 weeks) 4
• Consider tacrolimus 0.1% ointment once daily for 2-4 weeks for external eyelids and lid margins 4
• Pimecrolimus 1% cream may be effective for mild-to-moderate dermatitis on the face 4

For Infected Lesions

• Consider oral antibiotics for superinfected lesions 1
• Flucloxacillin is recommended for bacterial infections (commonly S. aureus) 4
• Erythromycin for penicillin-allergic patients 4

Common Pitfalls and Caveats

1. Undertreatment with systemic steroids: Emergency clinicians often prescribe systemic steroids for shorter durations than recommended (less than 14 days), which is associated with return visits 3

2. Overreliance on OTC topical steroids: Low-potency OTC corticosteroids (0.2-2.5% hydrocortisone) have not been shown to significantly improve symptoms 1

3. Delayed decontamination: The effectiveness of washing decreases dramatically within minutes of exposure 1

4. Misidentification of the plant: Educating patients on plant identification is crucial for prevention 5

5. Spreading misconceptions: The fluid from blisters does not spread the rash - only the urushiol oil from the plant can cause the reaction

Prevention

• Avoid contact with poison ivy, oak, and sumac plants
• Wear protective clothing when in areas where these plants may be present
• Use barrier creams before potential exposure
• Learn to identify these plants: "Leaves of three, let them be"

Toxicodendron dermatitis affects approximately 50-75% of individuals exposed to urushiol, with symptoms typically starting within days of exposure and lasting up to 3 weeks 1. The extent and severity of symptoms are proportional to the area and duration of exposure 1.

Remember that the rash from poison ivy is not contagious from person to person, and only those who have come in contact with the plant oil (urushiol) will develop the characteristic rash.