Is psoriasis itchy?

Psoriasis and Pruritus: Prevalence, Impact, and Management

Yes, psoriasis is commonly associated with itching (pruritus), affecting approximately 60-90% of patients with psoriasis, and is often considered one of the most bothersome symptoms of the disease. 1

Prevalence and Characteristics of Itch in Psoriasis

Pruritus is a significant symptom in psoriasis that has been historically underrecognized. Recent evidence shows:

• 60-90% of psoriasis patients experience itching 2, 3, 4
• For many patients, itching occurs on a daily basis 5
• Itch can involve the entire body but predominantly affects the legs, hands, back, and especially the scalp 4
• Itch intensity is typically moderate according to visual analog scale (VAS) measurements 6
• Itch tends to worsen in the evening and at night 5

Factors That Worsen Psoriatic Itch

Several factors have been identified that can exacerbate pruritus in psoriasis patients:

• Ambient heat (81% of patients) 5
• Skin dryness (80% of patients) 5
• Sweating (65% of patients) 5
• Stress (55% of patients) 5
• Higher body mass index (BMI) - overweight and obese patients tend to experience more severe itching 6

Impact on Quality of Life

The American Academy of Dermatology (AAD) and National Psoriasis Foundation (NPF) guidelines recognize that pruritus:

• Is often under-recognized in psoriasis patients 1
• Can have a major impact on a patient's quality of life 1
• Significantly affects daily functioning and psychosocial well-being 2
• Patients with itch show greater impairment of health-related quality of life compared to those without itch 2
• The intensity of itch correlates with the degree of quality-of-life reduction 2

Assessment of Pruritus

The AAD-NPF guidelines recommend:

• Itch severity assessment for patients whose psoriasis causes significant pruritus 1
• Several tools are available to assess this subjective symptom, with the visual analog scale (VAS) and numeric rating scale (NRS) being the most commonly used 1
• When assessing patients with these scales, a change of 3-4 points is considered clinically meaningful 1

Management Approaches

Disease-Modifying Treatments

Treatment of itch in psoriasis should primarily focus on resolving the skin lesions, as disease remission usually leads to itch relief 2:

1. Topical Therapies:

   • Topical corticosteroids and vitamin D analogs (calcipotriol) can provide temporary relief 6
   • Emollients help with skin dryness, which can worsen itch 6

2. Phototherapy:

   • Narrowband ultraviolet B (nb-UVB) has been shown to be one of the most effective treatments for reducing pruritus in psoriasis 6

3. Systemic Therapies:

   • Biologic agents have demonstrated efficacy in controlling itch 2, 6
   • Apremilast has shown important role in itch intensity reduction 2

Symptomatic Treatments

For direct itch management:

• Antihistamines, especially those with sedative effects, may provide some relief 2
• Antidepressants such as doxepin, mirtazapine, and paroxetine can help manage itch 2
• Cold showers have been reported to ameliorate itch in 55% of patients 5

Clinical Pearls and Pitfalls

• Pitfall: Assuming psoriasis is not pruritic. Historically, psoriasis was considered a non-pruritic dermatosis (in contrast to atopic dermatitis), leading to underappreciation of this symptom 4.

• Pitfall: Relying solely on antihistamines. Conventional antipruritic therapies like antihistamines have limited efficacy in psoriatic itch 3.

• Pitfall: Failing to assess itch severity. The AAD-NPF guidelines recommend formal assessment of itch severity when pruritus is significant 1.

• Pearl: Itch intensity does not necessarily correlate with Psoriasis Area and Severity Index (PASI) scores, meaning even patients with less extensive disease may experience significant pruritus 5.

• Pearl: Addressing modifiable factors like ambient heat, skin dryness, and stress may help reduce itch severity 5.