Psoriasis

Last reviewed: September 2018

Last updated: June 2018

Summary

Lesions are red, inflamed, silvery-white scaly, and circumscribed papules and plaques on elbows, knees, extensor limbs, and scalp. Psoriatic nails have a pitted surface and/or hypertrophic (subungual) changes.

Runs a variable course and seldom completely subsides. Severity is aggravated by genetic, infectious, emotional, and environmental factors.

Diagnosis is usually clinical.

Mild or limited psoriasis is treated with topical corticosteroids and/or vitamin D analogs.

Moderate to severe and/or extensive psoriasis may require phototherapy, and systemic agents such as oral retinoids, methotrexate, biologic agents, cyclosporine, or apremilast.

Definition

Psoriasis is a chronic inflammatory skin disease characterized by erythematous, circumscribed scaly papules and plaques on elbows, knees, extensor limbs, scalp, and, less commonly, nails, ears, and umbilical region. The disease is typically lifelong, with a fluctuating course of exacerbations and remission. It causes itching, irritation, burning, and stinging in half the cases. Although the classification typically includes psoriatic arthritis, skin manifestations only are discussed in this topic.

History and exam

Key diagnostic factors

skin lesions

Full details

Other diagnostic factors

FHx
skin discomfort

Full details

Risk factors

genetic
infection
local trauma
stress
smoking
light skin
alcohol intake (beer)

Full details

Diagnostic investigations

1st investigations to order

clinical diagnosis

Full details

Investigations to consider

skin biopsy

Full details

Treatment algorithm

ONGOING

plaque

guttate

pustular

Contributors

Authors VIEW ALL 

Andrea Chiricozzi, MD

Assistant Professor

University of Pisa

Consultant Dermatologist

University Hospital of Pisa

Pisa

Italy

Disclosures

AC has been reimbursed as a consultant and/or speaker for AbbVie, Biogen, Leo Pharma, Lilly, Janssen, and Novartis; AC is also the author of references cited in this topic.

Acknowledgements

Dr Andrea Chiricozzi would like to gratefully acknowledge Dr April W. Armstrong and Dr Tsu-Yi Chuang, previous contributors to this topic. TC declares that he has no competing interests. AWA is an investigator and consultant for Abbott, Amgen, and Janssen; AWA is also the author of references cited in this topic.

Peer reviewers VIEW ALL 

David Burden, MD, FRCP

Western Infirmary, Glasgow

Consultant Dermatologist Dermatology

Glasgow

Disclosures

DB is an author of a clinical practice guideline referenced in this topic. DB has been reimbursed as a consultant, researcher, and lecturer for Abbott, Leo, Pfizer, Merck, Janssen-Cilag, and Novartis.

Paradi Mirmirani, MD

Physician

Department of Dermatology

Kaiser Permanente Vallejo Medical Center

Vallejo

Disclosures

PM declares that she has no competing interests.

Use of this content is subject to our disclaimer

Psoriasis

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Treatment algorithm

plaque

guttate

pustular

Contributors

Authors VIEW ALL 

Andrea Chiricozzi, MD

Disclosures

Acknowledgements

Peer reviewers VIEW ALL 

David Burden, MD, FRCP

Disclosures

Paradi Mirmirani, MD

Disclosures

Differentials

Guidelines

Patient leaflets

Calculators

View PDF