Contact dermatitis

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Last reviewed: 24 Oct 2024

Last updated: 20 Jun 2023

Irritant contact dermatitis is caused by direct toxicity without prior sensitization, and allergic contact dermatitis is a delayed hypersensitivity reaction.

Results in localized burning, stinging, itching, blistering, redness, and swelling at the area of contact with the allergen or irritant.

Patch testing may aid identification of the causative agent. Skin biopsy may also be helpful, but may not be able to distinguish between other causes of dermatitis.

Treatment involves removal of the causative agent, future avoidance of the causative agent, topical treatments, or possibly a short course of oral corticosteroids, phototherapy, or immunosuppressants, depending on the type of contact dermatitis and severity.

Rarely, contact dermatitis can become generalized, leading to areas of dermatitis in locations distant from the site of contact with the causative agent.

Other allergic conditions may be triggered by exposure to an allergen, such as allergic rhinitis, asthma, and anaphylaxis.

Definition

Contact dermatitis is an allergic (immunologic) or irritant (nonimmunologic) skin reaction caused by an external agent.

History and exam

Key diagnostic factors

occupational history of exposure
history of atopic dermatitis
previous episodes of similar dermatitis
acute onset
affecting hands and face
affecting sun-exposed skin
sparing of non-exposed areas of skin
pruritus
burning
erythema
vesicles and bullae
urticaria
lichenoid lesions
corrosion or ulceration
pustules and acneiform lesions

Full details

Other diagnostic factors

scaling
lichenification
social history of exposure
persistence of symptoms
crusting
erythema multiforme
cellulitic lesions
leukoderma
hypopigmentation/depigmentation
hyperpigmentation
purpura
miliaria
alopecia
granulomatous lesions

Full details

Risk factors

occupation with frequent exposure to water or caustic material
atopic dermatitis

Full details

Diagnostic tests

1st tests to order

patch testing

Full details

Tests to consider

repeated open application test (ROAT) or provocative use test (PUT)
skin biopsy

Full details

Treatment algorithm

ACUTE

irritant contact dermatitis

allergic contact dermatitis (ACD)

ONGOING

contact dermatitis

Contributors

Authors

JiaDe Yu, MD, FAAD

Assistant Professor of Adult and Pediatric Dermatology

Director of Contact and Occupational Dermatology

Department of Dermatology

Massachusetts General Hospital

Harvard Medical School

Boston

Disclosures

JY was on the board for the American Contact Dermatitis Society from 2019-2022 (term ended and unpaid). JY has received a career development grant from the Dermatology Foundation and research grants from the Pediatric Dermatology Research Alliance and the American Contact Dermatitis Society. JY has received honorarium from the National Eczema Association for consultant work as part of its SEAL of approval project, and is on the editorial board for the Pediatric Dermatology journal and the Dermatitis journal.

Acknowledgements

Dr JiaDe Yu would like to gratefully acknowledge Dr Gerard Guillet, Dr David M. Ozog, and Dr Snehal Desai, previous contributors to this topic.

Disclosures

GG, DMO, and SD declare that they have no competing interests.

Peer reviewers

Christen Mowad, MD

Assistant Professor

Department of Dermatology

Geisinger Medical Center

Danville

Disclosures

CM declares that he has no competing interests.

John English, MBBS, FRCP

Consultant Dermatologist

Department of Dermatology

Queen's Medical Centre

Nottingham University Hospitals

Nottingham

Disclosures

JE declares that he has no competing interests.

Differentials
- Atopic dermatitis
- Nummular eczema
- Dyshidrotic eczema
More Differentials
Guidelines
- Pediatric allergic contact dermatitis. Part I: Clinical features and common contact allergens in children
- Pediatric allergic contact dermatitis. Part 2: Patch testing series, procedure, and unique scenarios
More Guidelines
Patient information
Dermatitis
More Patient information
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Contact dermatitis

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic tests

1st tests to order

Tests to consider

Treatment algorithm

irritant contact dermatitis

allergic contact dermatitis (ACD)

contact dermatitis

Contributors

Authors

JiaDe Yu, MD, FAAD

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Christen Mowad, MD

Disclosures

John English, MBBS, FRCP

Disclosures

Differentials

Guidelines

Patient information

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice