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Poison ivy, oak, and sumac

Last reviewed: 7 Feb 2026
Last updated: 03 Mar 2026

Summary

Definition

History and exam

Key diagnostic factors

  • pruritus
  • blisters and vesicles
  • weeping, oozing, and crusting
Full details

Other diagnostic factors

  • previous exposure
  • breathing difficulties
  • generalized erythroderma
  • periorbital edema
  • systemic contact dermatitis
  • black-spot dermatitis
Full details

Risk factors

  • occupation that involves exposure to relevant plants
  • outdoor activities
  • domestic pets and livestock
  • use of forestry equipment and machinery
  • smoke from burning Toxicodendron species
  • previous exposure or allergy to relevant plants
  • children
  • genetic susceptibility
Full details

Diagnostic tests

1st tests to order

  • clinical diagnosis
Full details

Tests to consider

  • botanical identification
  • black-spot test
  • CBC
Full details

Emerging tests

  • patch test

Treatment algorithm

INITIAL

immediate treatment postexposure

ACUTE

mild dermatitis

moderate dermatitis

severe dermatitis

ONGOING

chronic severe dermatitis from repeated exposure

Contributors

Authors

Marius Rademaker, BM FRCP, FRACP DM, FNZDSI, FACD

Clinical Trials New Zealand

Waikato Hospital Campus

Hamilton

New Zealand

Disclosures

MR declares that he has no competing interests.

Peer reviewers

Brian Swick, MD

Clinical Assistant Professor

University of Iowa College of Medicine

Iowa City

IA

Disclosures

BS declares that he has no competing interests.

Christopher Lovell, MBBS

Consultant Dermatologist

Kinghorn Dermatology Unit

Royal United Hospital

Bath

UK

Disclosures

CL declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Guin JD, Beaman JH, Baer H. Toxic anacardiaceae. In: Avalos J, Maibach HI, eds. Dermatologic botany. Boca Raton, FL: CRC Press; 1999.

Centers for Disease Control and Prevention. Poisonous plants and work. Aug 2024 [internet publication].Full text

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

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