Poison ivy, oak, and sumac
- Overview
- Theory
- Diagnosis
- Management
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Treatment algorithm
Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer
immediate treatment postexposure
washing with soap and water
Urushiols are absorbed quickly, so washing should begin within a few minutes of suspected exposure (but may still be of benefit up to 30 minutes later).
Forceful, unidirectional washing of exposed areas with a damp washcloth and liquid soap under hot running water is recommended to reduce or prevent toxicodendron dermatitis.[28]Neill BC, Neill JA, Brauker J, et al. Post-exposure prevention of toxicodendron dermatitis with early forceful unidirectional washing. J Am Acad Dermatol. 2018 Feb 1 [Epub ahead of print]. http://www.ncbi.nlm.nih.gov/pubmed/29410167?tool=bestpractice.com
Exposed clothing should be thoroughly washed with detergent but removed and handled while wearing vinyl gloves to prevent transfer of urushiols. Urushiols can penetrate rubber or latex.
commercial sprays to bind and remove allergen
Treatment recommended for SOME patients in selected patient group
If available, apply as soon as possible after exposure.
Tecnu® is a commercial organic solvent. It contains deodorized mineral spirits, propylene glycol, octylphenoxy-polyethoxyethanol, mixed fatty acid soap, and fragrance. Total protection (no clinical symptoms) in 70% of sensitized individuals when applied within 2 hours of exposure has been demonstrated in one study.[29]Stibich AS, Yagan M, Sharma V, et al. Cost-effective post-exposure prevention of poison ivy dermatitis. Int J Dermatol. 2000 Jul;39(7):515-8. http://www.ncbi.nlm.nih.gov/pubmed/10940115?tool=bestpractice.com
Zanfel® is a mixture of ethoxylate and lauroyl sarcosinate. A randomized, double-blind, placebo-controlled study reported improvement in erythema, induration, and vesiculation with use after laboratory exposure, compared with placebo.[30]Davila A, Lucas J, Laurora M, et al. A new topical agent, Zanfel, ameliorates urushiol-induced Toxicodendron allergic contact dermatitis [abstract 364]. Ann Emerg Med. 2003;42 (Suppl 4):s98.
mild dermatitis
low-to-moderate potency topical corticosteroid
If a patient presents with mild dermatitis, a moderate-potency topical corticosteroid (with or without occlusion) can be applied for 2 to 15 days.
A low-potency corticosteroid, for example, hydrocortisone, is recommended for thin-skinned areas.
Topical corticosteroids are rated on a potency scale from 1 (highest potency) to 7 (lowest potency). For example, fluticasone is class 3, triamcinolone is class 4, betamethasone valerate is class 5, and hydrocortisone is class 6/7, at the strengths given below.
Cream or gel base is best, as formulation affects potency.
Primary options
betamethasone valerate topical: children and adults: (0.1%) apply sparingly to the affected area(s) twice daily
or
triamcinolone topical: children and adults: (0.1%) apply sparingly to the affected area(s) twice daily
or
fluticasone propionate topical: children and adults: (0.005%) apply sparingly to the affected area(s) twice daily
-- AND / OR --
hydrocortisone topical: children and adults: (0.5 to 1%) apply sparingly to the affected area(s) twice daily
More hydrocortisone topicalAdvised for use on thin-skinned areas.
antihistamine and cold compress
Treatment recommended for SOME patients in selected patient group
Antihistamines provide symptomatic relief from itching.
Newer, selective antihistamines are of limited benefit; older sedating antihistamines are preferred.
A cold compress may help relieve itching but only in mild cases.
Primary options
chlorpheniramine: children 2-5 years of age: 1 mg every 4-6 hours when required, maximum 4 mg/day; children 6-12 years of age: 2 mg every 4-6 hours when required, maximum 12 mg/day; adults: 4 mg orally every 4-6 hours when required, maximum 24 mg/day
Secondary options
cetirizine: children 2-5 years of age: 2.5 to 5 mg orally once daily, maximum 5 mg/day; children 6-12 years of age and adults: 5-10 mg orally once daily, maximum 10 mg/day
OR
diphenhydramine: children 2-5 years of age: 6.25 mg orally every 4-6 hours, maximum 37.5 mg/day; children 6-11 years of age: 12.5 to 25 mg orally every 4-6 hours, maximum 150 mg/day; adults: 25-50 mg orally every 4-6 hours, maximum 400 mg/day
OR
hydroxyzine: children<6 years of age: 2 mg/kg/day orally given in divided doses every 6-8 hours; children 6-12 years of age: 12.5 to 25 mg orally every 6-8 hours when required; adults: 25-100 mg orally every 6 hours when required
OR
promethazine: children >2 years of age: 0.1 mg/kg orally every 6 hours, maximum 12.5 mg/dose during the day, 25 mg/dose at bedtime; adults: 6.25 to 12.5 mg orally every 8 hours
topical calcineurin inhibitor
A topical calcineurin inhibitor may be used if a corticosteroid is contraindicated and as an alternative to hydrocortisone in thin-skinned areas.
There have been rare reports of skin malignancy and lymphoma in patients treated with topical calcineurin inhibitors.[35]Siegfried EC, Jaworski JC, Hebert AA. Topical calcineurin inhibitors and lymphoma risk: evidence update with implications for daily practice. Am J Clin Dermatol. 2013 Jun;14(3):163-78. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3669499 http://www.ncbi.nlm.nih.gov/pubmed/23703374?tool=bestpractice.com
These agents are not indicated for use in children <2 years of age.
Tacrolimus is likely to be more effective than pimecrolimus, which may not be of sufficient potency except in the mildest of cases and tends to be used on the face.[31]Amrol D, Keitel D, Hagaman D, et al. Topical pimecrolimus in the treatment of human allergic contact dermatitis. Ann Allergy Asthma Immunol. 2003 Dec;91(6):563-6. http://www.ncbi.nlm.nih.gov/pubmed/14700441?tool=bestpractice.com
Treatment course is usually 2 to 15 days.
Primary options
tacrolimus topical: children ≥2 years of age and adults: (0.03%) apply sparingly to the affected area(s) twice daily; adults: (0.03% or 0.1%) apply sparingly to the affected area(s) twice daily
Secondary options
pimecrolimus topical: children ≥2 years of age and adults: (1%) apply sparingly to the affected area(s) twice daily
antihistamine and cold compress
Treatment recommended for SOME patients in selected patient group
Antihistamines provide symptomatic relief from itching.
Newer, selective antihistamines are of limited benefit; older sedating antihistamines are preferred.
A cold compress may help relieve itching but only in mild cases.
Primary options
chlorpheniramine: children 2-5 years of age: 1 mg every 4-6 hours when required, maximum 4 mg/day; children 6-12 years of age: 2 mg every 4-6 hours when required, maximum 12 mg/day; adults: 4 mg orally every 4-6 hours when required, maximum 24 mg/day
Secondary options
cetirizine: children 2-5 years of age: 2.5 to 5 mg orally once daily, maximum 5 mg/day; children 6-12 years of age and adults: 5-10 mg orally once daily, maximum 10 mg/day
OR
diphenhydramine: children 2-5 years of age: 6.25 mg orally every 4-6 hours, maximum 37.5 mg/day; children 6-11 years of age: 12.5 to 25 mg orally every 4-6 hours, maximum 150 mg/day; adults: 25-50 mg orally every 4-6 hours, maximum 400 mg/day
OR
hydroxyzine: children 2-5 years of age: 2 mg/kg/day every 6-8 hours; children 2-5 years of age: 12.5 to 25 mg every 6-8 hours; adults: 25-100 mg every 6 hours
OR
promethazine: children >2 years of age: 0.1 mg/kg orally every 6 hours, maximum 12.5 mg/dose during the day, 25 mg/dose at bedtime; adults: 6.25 to 12.5 mg orally every 8 hours
moderate dermatitis
high-potency topical corticosteroid or topical calcineurin inhibitor
In patients with moderate dermatitis, potent topical corticosteroids are indicated (with or without occlusion), for 7 to 21 days.
An ultra-potent topical corticosteroid can be tried if needed; clinicians should weigh the potential benefits and harms of higher-potency corticosteroids in patients with thin skin.
Topical corticosteroids are rated on a potency scale from 1 (highest potency) to 7 (lowest potency). For example, fluticasone is class 3, betamethasone dipropionate is class 2, and clobetasol is class 1 (at the given strengths below).
A cream or gel base is recommended.
Topical tacrolimus or pimecrolimus may be used as an alternative to a higher-potency topical corticosteroid. There have been rare reports of skin malignancy and lymphoma in patients treated with topical calcineurin inhibitors.[35]Siegfried EC, Jaworski JC, Hebert AA. Topical calcineurin inhibitors and lymphoma risk: evidence update with implications for daily practice. Am J Clin Dermatol. 2013 Jun;14(3):163-78. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3669499 http://www.ncbi.nlm.nih.gov/pubmed/23703374?tool=bestpractice.com These agents are not indicated for use in children <2 years of age. Treatment course is usually 2 to 15 days.
Primary options
fluticasone propionate topical: children and adults: (0.005%) apply sparingly to the affected area(s) twice daily
OR
betamethasone dipropionate topical: children and adults: (0.05%) apply sparingly to the affected area(s) twice daily
OR
clobetasol topical: children and adults: (0.05%) apply sparingly to the affected area(s) twice daily
Secondary options
tacrolimus topical: children ≥2 years of age and adults: (0.03%) apply sparingly to the affected area(s) twice daily; adults: (0.03% or 0.1%) apply sparingly to the affected area(s) twice daily
OR
pimecrolimus topical: children ≥2 years of age and adults: (1%) apply sparingly to the affected area(s) twice daily
antihistamine
Treatment recommended for SOME patients in selected patient group
Antihistamines provide symptomatic relief from itching.
Newer, selective antihistamines are of limited benefit; older sedating antihistamines are preferred.
Primary options
chlorpheniramine: children 2-5 years of age: 1 mg every 4-6 hours when required, maximum 4 mg/day; children 6-12 years of age: 2 mg every 4-6 hours when required, maximum 12 mg/day; adults: 4 mg orally every 4-6 hours when required, maximum 24 mg/day
Secondary options
cetirizine: children 2-5 years of age: 2.5 to 5 mg orally once daily, maximum 5 mg/day; children 6-12 years of age and adults: 5-10 mg orally once daily, maximum 10 mg/day
OR
diphenhydramine: children 2-5 years of age: 6.25 mg orally every 4-6 hours, maximum 37.5 mg/day; children 6-11 years of age: 12.5 to 25 mg orally every 4-6 hours, maximum 150 mg/day; adults: 25-50 mg orally every 4-6 hours, maximum 400 mg/day
OR
hydroxyzine: children 2-5 years of age: 2 mg/kg/day every 6-8 hours; children 2-5 years of age: 12.5 to 25 mg every 6-8 hours; adults: 25-100 mg every 6 hours
OR
promethazine: children >2 years of age: 0.1 mg/kg orally every 6 hours, maximum 12.5 mg/dose during the day, 25 mg/dose at bedtime; adults: 6.25 to 12.5 mg orally every 8 hours
systemic corticosteroid
If symptoms deteriorate or fail to improve with topical corticosteroids, second-line treatment is systemic corticosteroids. The treatment course is usually 7 to 21 days.
The dose needs to be tapered once control is achieved, but if done too early may result in a flare-up of the dermatitis. If this occurs, the dose can be increased and tapered more slowly.
If compliance with oral therapy is difficult, an intramuscular injection of triamcinolone acetonide may be given and repeated weekly while symptoms persist.
Primary options
prednisone: children and adults: 0.5 to 1 mg/kg orally once daily
Secondary options
triamcinolone acetonide: adults: 40 mg intramuscularly as a single dose, repeat in 7-10 days if symptoms flare, smaller doses required in children
More triamcinolone acetonideTriamcinolone acetonide salt is used.
antihistamine
Treatment recommended for SOME patients in selected patient group
Antihistamines provide symptomatic relief from itching.
Newer, selective antihistamines are of limited benefit; older sedating antihistamines are preferred.
Primary options
chlorpheniramine: children 2-5 years of age: 1 mg every 4-6 hours when required, maximum 4 mg/day; children 6-12 years of age: 2 mg every 4-6 hours when required, maximum 12 mg/day; adults: 4 mg orally every 4-6 hours when required, maximum 24 mg/day
Secondary options
cetirizine: children 2-5 years of age: 2.5 to 5 mg orally once daily, maximum 5 mg/day; children 6-12 years of age and adults: 5-10 mg orally once daily, maximum 10 mg/day
OR
diphenhydramine: children 2-5 years of age: 6.25 mg orally every 4-6 hours, maximum 37.5 mg/day; children 6-11 years of age: 12.5 to 25 mg orally every 4-6 hours, maximum 150 mg/day; adults: 25-50 mg orally every 4-6 hours, maximum 400 mg/day
OR
hydroxyzine: children 2-5 years of age: 2 mg/kg/day every 6-8 hours; children 2-5 years of age: 12.5 to 25 mg every 6-8 hours; adults: 25-100 mg every 6 hours
OR
promethazine: children >2 years of age: 0.1 mg/kg orally every 6 hours, maximum 12.5 mg/dose during the day, 25 mg/dose at bedtime; adults: 6.25 to 12.5 mg orally every 8 hours
severe dermatitis
systemic corticosteroid
Commence high-dose oral corticosteroids. The treatment course is usually 7 to 21 days.
The dose needs to be tapered once control is achieved, but if done too early may result in a flare-up of the dermatitis. If this occurs, the dose can be increased and tapered more slowly.
If compliance with oral therapy is an issue, an intramuscular injection of triamcinolone acetonide can be given and repeated weekly while symptoms persist.
Primary options
prednisone: children and adults: 0.5 to 1 mg/kg orally once daily
Secondary options
triamcinolone acetonide: adults: 40 mg intramuscularly as a single dose, repeat in 7-10 days if symptoms flare, smaller doses recommended in children
More triamcinolone acetonideTriamcinolone acetonide salt is used.
high-potency topical corticosteroid or topical calcineurin inhibitor
Treatment recommended for ALL patients in selected patient group
Use potent topical corticosteroids in combination with oral corticosteroids for 7 to 21 days.
Topical corticosteroids are rated on a potency scale from 1 (highest potency) to 7 (lowest potency). For example, at the given strengths below, betamethasone dipropionate is class 2 and clobetasol is class 1.
A cream or gel base is recommended.
Topical tacrolimus or pimecrolimus may be used as an alternative to a higher-potency topical corticosteroid. There have been rare reports of skin malignancy and lymphoma in patients treated with topical calcineurin inhibitors.[35]Siegfried EC, Jaworski JC, Hebert AA. Topical calcineurin inhibitors and lymphoma risk: evidence update with implications for daily practice. Am J Clin Dermatol. 2013 Jun;14(3):163-78. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3669499 http://www.ncbi.nlm.nih.gov/pubmed/23703374?tool=bestpractice.com These agents are not indicated for use in children <2 years of age. Treatment course is usually 2 to 15 days.
Primary options
betamethasone dipropionate topical: children and adults: (0.05%) apply sparingly to the affected area(s) twice daily
OR
clobetasol topical: children and adults: (0.05%) apply sparingly to the affected area(s) twice daily
Secondary options
tacrolimus topical: children ≥2 years of age and adults: (0.03%) apply sparingly to the affected area(s) twice daily; adults: (0.03% or 0.1%) apply sparingly to the affected area(s) twice daily
OR
pimecrolimus topical: children ≥2 years of age and adults: (1%) apply sparingly to the affected area(s) twice daily
antihistamine
Treatment recommended for SOME patients in selected patient group
Sedating antihistamines may help in severe dermatitis if symptoms disturb sleep. These are preferred to newer, selective antihistamines, which are of limited benefit.
These are preferred to newer, selective antihistamines that are of limited benefit.
Primary options
chlorpheniramine: children 2-5 years of age: 1 mg every 4-6 hours when required, maximum 4 mg/day; children 6-12 years of age: 2 mg every 4-6 hours when required, maximum 12 mg/day; adults: 4 mg orally every 4-6 hours when required, maximum 24 mg/day
Secondary options
cetirizine: children 2-5 years of age: 2.5 to 5 mg orally once daily, maximum 5 mg/day; children 6-12 years of age and adults: 5-10 mg orally once daily, maximum 10 mg/day
OR
diphenhydramine: children 2-5 years of age: 6.25 mg orally every 4-6 hours, maximum 37.5 mg/day; children 6-11 years of age: 12.5 to 25 mg orally every 4-6 hours, maximum 150 mg/day; adults: 25-50 mg orally every 4-6 hours, maximum 400 mg/day
OR
hydroxyzine: children 2-5 years of age: 2 mg/kg/day every 6-8 hours; children 2-5 years of age: 12.5 to 25 mg every 6-8 hours; adults: 25-100 mg every 6 hours
OR
promethazine: children >2 years of age: 0.1 mg/kg orally every 6 hours, maximum 12.5 mg/dose during the day, 25 mg/dose at bedtime; adults: 6.25 to 12.5 mg orally every 8 hours
chronic severe dermatitis from repeated exposure
immunosuppressive therapy
Individuals repeatedly exposed to poison ivy, oak, and sumac may develop severe chronic dermatitis.
Consider using long-term immunosuppressive agents such as cyclosporine, azathioprine, or mycophenolate if ongoing exposure cannot be avoided.
Azathioprine may take 3 to 6 months to be effective. Before commencing therapy it is advisable to check levels of thiopurine methyltransferase and, if low, reduce the initial dose according to local guidelines.
Primary options
azathioprine: 1-3 mg/kg/day orally given in 2 divided doses
OR
cyclosporine modified: 3-5 mg/kg/day orally given in 2 divided doses
OR
mycophenolate mofetil: 1 to 1.5 g orally twice daily
Choose a patient group to see our recommendations
Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer
Use of this content is subject to our disclaimer