How should poison‑ivy dermatitis be managed in adults, children, and pregnant patients, including initial washing, topical and systemic therapies, and special considerations for extensive rash?

Management of Poison Ivy Dermatitis

Wash the exposed area immediately with soap and water or any available cleaning product—this is the single most effective intervention and can remove up to 100% of urushiol if done within minutes, though even washing up to 2 hours later reduces symptoms by 55-70%. 1

Immediate Decontamination (First 2 Hours)

• Wash as soon as possible after exposure with soap and water, commercial decontamination products, hand cleaners, or even dishwashing soap—all show similar effectiveness 1, 2
• Effectiveness decreases rapidly: 100% removal if immediate, 50% at 10 minutes, 10% at 30 minutes, but still 55-70% symptom reduction even at 2 hours 1, 2
• Remove and wash all contaminated clothing and objects that contacted the plant 3

Symptomatic Relief for All Patients

• Apply cool compresses to affected areas for local symptom relief 1
• Oatmeal baths may provide relief for itching and inflammation 1
• Avoid scratching to prevent secondary bacterial infection 4

Topical Treatment Based on Severity

Mild Cases (<10% Body Surface Area)

• Over-the-counter hydrocortisone (0.2-2.5%) has uncertain effectiveness with low-quality evidence showing no significant symptom improvement 1
• High-potency prescription topical corticosteroids (clobetasol 0.05% or fluocinonide 0.05% cream/ointment) are more effective 4
• Avoid greasy topical products as they inhibit wound exudate absorption and promote superinfection 4

Moderate Cases (10-30% BSA)

• High-potency prescription topical corticosteroids should be used 4
• Consider adding oral antihistamines for nighttime sedation, though evidence for itch reduction is uncertain 1

Systemic Corticosteroids for Severe Cases

For severe cases (>30% BSA) or significant facial/genital involvement, prescribe systemic corticosteroids combined with high-potency topical steroids—this combination reduces the duration of itching with moderate-strength evidence. 1

• Oral prednisone is the standard systemic treatment for severe cases 4, 5
• Treatment typically requires 2-3 weeks duration as the dermatitis is self-limiting 1, 5, 6
• Intravenous methylprednisolone may be needed for hospitalized patients with extensive involvement 4

Special Population Considerations

Children

• Same management principles apply as for adults 6
• Ensure adequate supervision to prevent scratching and secondary infection 4

Pregnant Patients

• Topical corticosteroids are generally safe 4
• Systemic corticosteroids should be used cautiously and only when benefits outweigh risks, as with any medication in pregnancy 4
• Cool compresses and oatmeal baths are safe non-pharmacologic options 1

Monitoring for Complications

• Assess for secondary bacterial infection: increased warmth, tenderness, purulent drainage, honey-colored crusting, or surrounding cellulitis 7
• Document percentage of BSA involved to guide treatment escalation 7
• If symptoms worsen after 2 weeks, consider continued allergen exposure or complications 7

Critical Pitfalls to Avoid

• Do not rely on low-potency OTC hydrocortisone for anything beyond the mildest cases—evidence shows it doesn't work 1
• Do not use greasy ointments or occlusive products that trap moisture 4
• Do not prescribe short courses (<2 weeks) of systemic steroids for severe cases, as rebound dermatitis may occur 5, 6
• Remember that approximately 50-75% of individuals react to urushiol, so negative history doesn't rule out future reactions 1

When to Refer or Escalate

• Systemic involvement requiring physician consultation 6
• Severe cases with >30% BSA involvement 7
• Signs of secondary bacterial infection requiring antibiotics 7
• Facial or genital involvement causing significant functional impairment 3