What are the treatments for poison ivy and shingles?

Treatment for Poison Ivy and Shingles

Poison Ivy Treatment

For mild to moderate poison ivy dermatitis, 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, and add oral antihistamines for pruritus relief. 1

Mild Cases (Localized Disease)

• Apply mid-potency topical corticosteroids like prednicarbate cream to affected areas twice daily 2
• Use oral antihistamines: 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 sedative properties 1
• Apply alcohol-free moisturizing creams or ointments twice daily, preferably with urea-containing (5%-10%) moisturizers 1

Moderate Cases (10-30% Body Surface Area)

• Continue topical moderate-to-high potency corticosteroids applied twice daily 1
• Add oral antihistamines for symptom control 1
• Consider combining topical high-potency steroids plus a short systemic corticosteroid course if symptoms limit daily activities 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 1

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

• Initiate systemic corticosteroids immediately with prednisone 0.5-1 mg/kg body weight for 7 days, followed by a weaning dose over 4-6 weeks 1
• Continue topical corticosteroids to affected areas 1
• Add oral antihistamines for symptomatic relief 1
• Critical: Ensure systemic corticosteroid tapers are long enough (4-6 weeks) to prevent rebound flare 1

Supportive Care for All Severities

• Avoid frequent washing with hot water 1
• Avoid skin irritants including over-the-counter anti-acne medications, solvents, or disinfectants 1
• Apply sunscreen SPF 15 to exposed areas every 2 hours when outside 1

Warning Signs Requiring Antibiotics

• Check for increased warmth, tenderness, purulent drainage, honey-colored crusting, or cellulitis, which require antibiotic therapy 1

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Shingles (Herpes Zoster) Treatment

For immunocompetent adults with shingles, initiate famciclovir 500 mg every 8 hours for 7 days, starting within 72 hours of rash onset for maximum efficacy. 3

Antiviral Therapy

• Famciclovir 500 mg every 8 hours for 7 days is FDA-approved for herpes zoster in immunocompetent adults 3
• Treatment should be initiated as soon as possible after diagnosis, ideally within 72 hours of rash onset 3
• For HIV-infected patients with recurrent orolabial or genital herpes: famciclovir 500 mg twice daily for 7 days 3

Dose Adjustments

• Adjust dose based on creatinine clearance in patients with renal impairment to prevent acute renal failure 3
• Acute renal failure may occur in patients with underlying renal disease who receive higher than recommended doses 3

Symptomatic Management

• Topical corticosteroids are not routinely recommended for shingles, as the primary treatment is antiviral therapy 3
• Pain management should be addressed separately based on severity

Contraindications

• Known hypersensitivity to famciclovir, its components, or penciclovir cream 3

Limitations

• Efficacy and safety have not been established for ophthalmic zoster (requires urgent ophthalmology referral) 3
• Not established for immunocompromised patients other than HIV-infected patients with recurrent orolabial or genital herpes 3

Drug Interactions

• Probenecid may increase penciclovir levels; monitor for evidence of penciclovir toxicity 3

Common Adverse Events

• Headache and nausea occur in greater than 10% of patients 3