NCLEX Review Guide: Pharmacology - Integumentary System - Poison Ivy Treatment

Contact Dermatitis Overview

• Urushiol is the allergenic oil in poison ivy that causes delayed hypersensitivity reaction (Type IV) occurring 12-72 hours after exposure.
• Clinical manifestations include erythema, vesicles, bullae, intense pruritus, and linear distribution patterns following plant contact.
• Reaction severity depends on individual sensitivity, amount of urushiol exposure, and previous sensitization history.

Topical Medications

• Calamine lotion provides cooling, drying effect for weeping lesions and mild pruritus relief through zinc oxide and ferric oxide.
• Hydrocortisone 1% cream reduces inflammation and itching for mild cases, applied 2-3 times daily to affected areas.
• Cool compresses with Burow's solution (aluminum acetate) help dry vesicles and reduce inflammation when applied 15-20 minutes TID.

Systemic Medications

• Oral antihistamines (diphenhydramine 25-50mg q6h, loratadine 10mg daily) reduce pruritus and provide sedation for nighttime comfort.
• Oral prednisone 40-60mg daily x 10-14 days for severe, widespread reactions covering >10% body surface area or facial involvement.
• Antibiotics (cephalexin, clindamycin) indicated only for secondary bacterial infection with purulent drainage, increased warmth, or red streaking.

Immediate Care

1. Remove contaminated clothing and wash with hot, soapy water immediately
2. Cleanse affected skin with dish soap or specialized poison ivy wash within 10 minutes if possible
3. Apply cool, wet compresses to reduce inflammation and provide comfort
4. Trim fingernails short to prevent scratching and secondary infection

Patient Education

• Teach proper identification of poison ivy: "Leaves of three, let it be" with characteristic three-leaflet pattern.
• Emphasize washing clothes, tools, and pets that may have contacted the plant using hot, soapy water and gloves.
• Instruct on signs of secondary infection requiring medical attention: fever, pus, red streaking, or worsening after 7-10 days.

Frequently Missed Concepts

• NEVER apply topical antihistamines (like Benadryl cream) to poison ivy as they can cause additional contact sensitization.
• Oral steroids require gradual taper for courses longer than 7 days to prevent adrenal insufficiency.
• Cool (not cold) water is preferred - ice can cause tissue damage and worsen inflammation.

Assessment Priorities

• Monitor for signs of systemic reaction: difficulty breathing, widespread swelling, or severe facial involvement requiring emergency care.
• Assess for secondary bacterial infection: increased pain, purulent drainage, fever, or lymphangitis (red streaking).