10 psoriasis facts

1. Psoriasis is a chronic inflammatory skin condition characterised by well-demarcated, scaly, erythematous plaques
2. Prevalence is very common in the UK, affecting 2% of the population
3. Cause is unknown but multifactorial: genetic predisposition, environmental factors, and immune system dysfunction contribute to its development
4. Diagnosis is primarily clinical, supported by history and physical examination
5. Treatment options include topical treatments, light therapy, and systemic medications.

1. Definition

• Psoriasis is a chronic, non-communicable skin condition characterized by abnormal keratinocyte proliferation and immune system dysregulation.
• Results in inflammation and scaling of the skin, leading to significant physical and psychological morbidity.

Types

• Plaque psoriasis – is the most common type of psoriasis. About 80-90% have plaque psoriasis
• Inverse psoriasis– appears in skin folds. It causes thin plaques without scales
• Guttate psoriasis – may appear after a sore throat caused by a streptococcal infection. It looks like small, red, drop-shaped scaly spots and often affects children and young adults
• Pustular psoriasis – has small, pus-filled bumps on top of plaques
• Erythrodermic psoriasis – is a severe type of psoriasis that affects a large area (more than 90%) of your skin. which causes red and scaly skin over much of your body.
• Nail psoriasis – causes skin discoloration, pitting and changes to fingernails and toenails.

2. Epidemiology

• Estimated prevalence in the UK: 2% (approximately 1.5 million people)
• More common in Caucasians than other ethnic groups
• Peak onset: 20-30 years and 50-60 years
• Female-to-male ratio: 1:1.

• Family history (first-degree relative)
• Obesity
• Smoking
• Excessive alcohol consumption
• Stress
• Certain medications (e.g. lithium, beta-blockers)
• Infections (e.g. streptococcal infections).

• Genetic predisposition (HLA-Cw6, PSORS1)
• Immune system dysfunction (T-cell activation, cytokine imbalance)
• Environmental triggers (e.g. skin trauma, cold weather)
• Abnormal keratinocyte proliferation and differentiation.

• Well-demarcated, erythematous plaques with silvery scales

• Commonly affected areas: elbows, knees, scalp, lower back
• Itching, burning, or stinging sensations
• Skin cracking and bleeding
• Nail changes (e.g. pitting, onycholysis)

• Joint pain or stiffness (psoriatic arthritis).

• Primarily clinical, based on history and physical examination
• Characteristic skin lesions and distribution
• Supportive features: nail changes, scalp involvement.

• Skin biopsy (to confirm diagnosis or rule out other conditions)
• Blood tests (e.g. inflammatory markers, liver function)
• Joint imaging (e.g. x-rays, ultrasound) for suspected psoriatic arthritis.

• Eczema (atopic dermatitis)
• Seborrhoeic dermatitis
• Contact dermatitis
• Lichen planus
• Cutaneous lupus erythematosus.

7. Treatment

• Topical treatment
  • Corticosteroids
  • Vitamin D analogues (e.g. calcipotriol)
  • Topical retinoids
• Light therapy
  • UVB phototherapy
  • Psoralen plus UVA (PUVA)
• Systemic medication
  • Methotrexate
  • Cyclosporin
  • Biological agents (e.g. etanercept, adalimumab)
• Lifestyle modification
  • Weight management
  • Smoking cessation
  • Stress reduction.

• New onset of skin lesions or symptoms
• Worsening or unresponsive symptoms
• Joint pain or stiffness
• Suspicion of complications (e.g. skin infections, eye problems).

• Skin infections (e.g. bacterial, fungal)
• Eye problems (e.g. uveitis, conjunctivitis)
• Psoriatic arthritis
• Cardiovascular disease
• Depression and anxiety.

• Chronic condition with variable disease course
• Response to treatment varies between individuals
• Early treatment and lifestyle modifications can improve outcomes.

• Maintain a healthy lifestyle (e.g. balanced diet, regular exercise)
• Manage stress
• Avoid triggers (e.g. smoking, excessive alcohol, drugs known to cause or worsen psoriasis)
• Regular skin checks and monitoring for complications.

Summary

We have described 10 facts about psoriasis. We hope it has been helpful.

Top Tip

If psoriasis is not improving, arrange a dermatology opinion (partly to consider biological agents).