Psoriasis
This article is general health information for the selected condition. It is not a diagnosis and does not replace clinical judgement. If you have questions or need treatment advice, please consult a qualified healthcare professional.
What is psoriasis?
Psoriasis is a chronic immune mediated condition in which skin cells are produced far faster than normal, forming thickened red plaques with silvery scale. It is not contagious. It is increasingly recognised as a systemic inflammatory disease associated with arthritis, cardiovascular disease and metabolic syndrome, so care extends beyond the skin.
Causes
- Immune activation driving rapid keratinocyte turnover
- Genetic predisposition including HLA C 06:02
- Streptococcal throat infection triggering guttate psoriasis
- Skin trauma producing the Koebner phenomenon
- Certain medicines including lithium and beta blockers
- Stress and smoking
Symptoms
- Well defined raised plaques with silvery scale
- Typical distribution on elbows, knees, scalp and lower back
- Itching or burning
- Cracking and bleeding of plaques
- Nail pitting, thickening or separation
- Joint pain and swelling in psoriatic arthritis
- Flares after infection, stress or skin injury
Risk factors
- Family history of psoriasis
- Smoking
- Obesity
- Excess alcohol
- Streptococcal infection
- Psychological stress
Diagnosis
- Clinical diagnosis from plaque appearance and distribution
- Nail and scalp examination
- Skin biopsy only in atypical cases
- Screening for psoriatic arthritis with a validated questionnaire
- Cardiovascular and metabolic risk assessment
Treatment
- Emollients to reduce scale and cracking
- Topical vitamin D analogues and corticosteroids
- Coal tar and salicylic acid preparations
- Narrowband UVB phototherapy
- Methotrexate, ciclosporin or acitretin for extensive disease
- Biologic therapies targeting TNF, IL 17 or IL 23
- Smoking cessation, weight management and alcohol reduction
Self care
- Use emollients generously to reduce scale and cracking
- Apply topical treatments consistently rather than intermittently
- Avoid picking or scratching plaques, which triggers new lesions
- Stop smoking and reduce alcohol
- Manage weight, which improves treatment response
- Get some natural sunlight, avoiding burning
- Manage stress, a common flare trigger
When to see a doctor
Book an appointment if:
- Plaques not responding to topical treatment
- Psoriasis affecting more than a small area
- Joint pain, swelling or stiffness
- Nail changes
- Significant impact on mood or confidence
- Sudden widespread flare after a sore throat
Some symptoms need emergency care rather than an appointment. See the warning signs listed above.
Prevention
- Psoriasis cannot be prevented, but flares can be reduced
- Avoid skin trauma, which triggers new plaques
- Stop smoking and limit alcohol
- Manage stress and treat streptococcal throat infections
- Maintain a healthy weight
- Review medicines that can trigger flares
Outlook
Psoriasis is a lifelong relapsing condition, but treatment options have expanded greatly. Most people control it with topical therapy, and biologics can clear severe disease almost completely. Around a third develop psoriatic arthritis, which is why joint symptoms should always be reported early, since joint damage is preventable but not reversible.
Common questions
Is psoriasis contagious?
No. It cannot be passed to anyone by touch, sharing towels, swimming or any other contact. It is an immune mediated condition with a strong genetic component.
Why is joint pain important to report?
Around one in three people with psoriasis develops psoriatic arthritis, which can permanently damage joints if untreated. Early recognition allows treatment that protects joint structure.
Does psoriasis affect general health?
Yes. It is associated with increased cardiovascular risk, metabolic syndrome, fatty liver disease and depression, so blood pressure, lipids, glucose and mood are typically reviewed alongside the skin.
References
Important: Dard AI is not a medical device and does not diagnose, treat, or replace clinician judgement. This article is general information only. Always consult a qualified healthcare professional about diagnosis and treatment, and seek emergency care for severe or rapidly worsening symptoms.