What are the recommended treatments for symptomatic relief of poison ivy exposure in a pregnant woman at 39 weeks gestation?

Management of Poison Ivy Exposure in Late Pregnancy (39 Weeks)

For symptomatic relief of poison ivy exposure in a pregnant woman at 39 weeks gestation, immediate washing with soap and water followed by cool compresses and low-potency topical hydrocortisone is recommended as first-line treatment, with oral antihistamines (preferably chlorphenamine) reserved for severe itching. 1, 2

Immediate Decontamination

• Wash the exposed area thoroughly with soap and water as soon as possible to remove urushiol oil
  • Effectiveness decreases rapidly with time: 100% effective immediately, 50% at 10 minutes, 25% at 15 minutes 1
  • Even washing 2 hours after exposure can reduce symptoms by 55-70% 1
• Remove and wash all clothing that may have contacted the plant

First-Line Symptomatic Treatment

1. Topical treatments:

   • Cool compresses to reduce inflammation and provide relief 1
   • Oatmeal baths to soothe itching 1
   • Over-the-counter hydrocortisone cream (FDA-approved for poison ivy) 3
     • Apply thinly to affected areas 2-4 times daily
     • Note: While OTC hydrocortisone has limited effectiveness according to some sources, it remains FDA-approved for this indication and is safe in pregnancy 1, 3

2. For moderate to severe itching:

   • Oral antihistamines may be considered with caution
   • Chlorphenamine (4-12mg) is preferred in pregnancy due to its long safety record 2
   • Best used at night to help with sleep disruption from itching 2

Important Pregnancy Considerations

• Avoid all antihistamines if possible, especially during first trimester, though this is less concerning at 39 weeks 2
• Hydroxyzine is specifically contraindicated in early pregnancy 2
• If antihistamines are necessary, chlorphenamine is often chosen by UK clinicians due to its established safety record 2
• Loratadine and cetirizine are FDA Pregnancy Category B drugs (no evidence of harm to fetus, but well-controlled human studies are lacking) 2

When to Seek Additional Medical Care

• For severe or widespread rash
• If the rash involves the face, eyes, or genitals
• If there are signs of infection (increased pain, pus, swelling, warmth)
• If there is difficulty breathing or swallowing (emergency)

Treatments to Avoid in Pregnancy

• Systemic corticosteroids (prednisolone, etc.) should be avoided unless absolutely necessary
• High-potency topical steroids
• Experimental treatments or homeopathic remedies with limited evidence 4

Expected Course

• Poison ivy dermatitis is typically self-limiting, lasting 2-3 weeks 5, 6
• The characteristic linear or streak-like appearance helps with diagnosis 6
• Severity depends on area of exposure, duration of contact, and individual sensitivity 1

Remember that at 39 weeks gestation, the pregnancy is near term, making treatment decisions somewhat less restrictive than in early pregnancy, but caution is still warranted with any medication use.