What is the recommended treatment for poison ivy?

Treatment of Poison Ivy Dermatitis

For mild to moderate poison ivy dermatitis, use topical corticosteroids (hydrocortisone 2.5% or moderate-potency steroids like mometasone furoate 0.1% or betamethasone valerate 0.1%), while severe cases require systemic corticosteroids (prednisone 0.5-1 mg/kg for 7 days with a 4-6 week taper). 1, 2

Treatment Algorithm by Severity

Mild Cases (<10% Body Surface Area)

• Apply topical corticosteroids such as hydrocortisone 2.5% or moderate-to-high potency steroids (mometasone furoate 0.1% ointment or betamethasone valerate 0.1% ointment) twice daily to affected areas 2, 1
• Topical corticosteroids are FDA-approved specifically for poison ivy, oak, and sumac dermatitis 1
• Add oral antihistamines for pruritus relief: non-sedating second-generation antihistamines (loratadine 10 mg daily) during daytime, or first-generation antihistamines (diphenhydramine 25-50 mg or hydroxyzine 25-50 mg) at night for their sedative properties 2
• Reassess after 2 weeks; if no improvement, escalate treatment 2

Moderate Cases (10-30% Body Surface Area or Significant Symptoms)

• Continue topical moderate-to-high potency corticosteroids applied twice daily 2
• Add oral antihistamines for symptom control 2
• Consider GABA agonists (pregabalin 25-150 mg daily or gabapentin 900-3600 mg daily) as second-line therapy if antihistamines fail to control pruritus 2
• Monitor closely for progression to severe disease 3

Severe Cases (>30% Body Surface Area or Limiting Self-Care)

• Initiate systemic corticosteroids immediately: prednisone 0.5-1 mg/kg body weight for 7 days, followed by a weaning dose over 4-6 weeks 2
• Continue topical corticosteroids to affected areas 2
• Add oral antihistamines for symptomatic relief 2
• If infection is suspected (painful lesions, purulent discharge, yellow crusts, failure to respond to treatment), obtain bacterial cultures and start antibiotics for at least 14 days based on sensitivities 2, 3

Supportive Care Measures

Immediate Management

• Wash exposed skin with a lipid-soluble solvent immediately after contact, ideally within 2 hours of exposure 4, 5
• Apply cold compresses for symptomatic relief 5
• Use alcohol-free moisturizing creams or ointments twice daily, preferably with urea-containing (5%-10%) moisturizers 2

Skin Care During Treatment

• Avoid frequent washing with hot water 2
• Avoid skin irritants including over-the-counter anti-acne medications, solvents, or disinfectants 2
• Apply sunscreen SPF 15 to exposed areas every 2 hours when outside 2

Critical Pitfalls to Avoid

Inadequate corticosteroid duration: The dermatitis typically lasts 1-3 weeks, so ensure systemic corticosteroid tapers are long enough (4-6 weeks) to prevent rebound flare 2, 6, 7

Continued allergen exposure: Worsening after 2 weeks suggests ongoing contact with the oleoresin from contaminated clothing, tools, or pet fur 3, 6

Missing secondary infection: Check for increased warmth, tenderness, purulent drainage, honey-colored crusting, or cellulitis, which require antibiotic therapy 2, 3

Using topical corticosteroids alone for severe cases: Systemic corticosteroids are necessary when >30% body surface area is involved or self-care is limited 2, 3