What is the treatment for multiple thickened, pruritic, scaly plaques on the knees, elbows, and back that bleed when peeled off, suggestive of psoriasis?

Treatment for Chronic Plaque Psoriasis

For these characteristic psoriatic plaques, initiate treatment with topical corticosteroids combined with vitamin D analogs as first-line therapy, which provides superior efficacy and reduced irritation compared to monotherapy. 1, 2

Initial Assessment and Severity Classification

The clinical presentation of thickened, pruritic, scaly plaques on extensor surfaces (knees, elbows) and back that bleed when removed (Auspitz sign) is diagnostic of chronic plaque psoriasis. 1, 3

Severity determination should include:

• Body surface area (BSA) involvement: <5% BSA indicates mild disease; ≥5% BSA indicates moderate-to-severe disease 1, 4
• Symptomatic burden: The presence of pruritus and bleeding qualifies this patient for escalated therapy regardless of BSA 1, 4
• Quality of life impact: Even limited involvement can warrant systemic therapy if significantly debilitating 3, 2

First-Line Topical Treatment Algorithm

Start with combination topical therapy:

• Topical corticosteroid (moderate-to-potent strength) PLUS vitamin D analog (calcipotriene): This combination achieves enhanced efficacy with reduced irritation compared to either agent alone 1, 2, 4
• Apply no more than 100g monthly of moderately potent corticosteroid to minimize systemic absorption and skin atrophy 1
• Require regular clinical review with no unsupervised repeat prescriptions 1
• Plan periods each year when alternative treatment is employed to prevent tachyphylaxis and long-term adverse effects 1

Alternative first-line topical agents if combination therapy fails:

• Coal tar preparations: Start with 0.5-1.0% crude coal tar in petroleum jelly, increasing to maximum 10% concentration every few days 1, 3
• Dithranol (anthralin): Proven effective but requires adequate patient education regarding application technique 1, 3

When to Escalate Beyond Topical Therapy

Consider phototherapy or systemic therapy if the patient meets ANY of the following criteria:

• Symptomatic disease with pain, bleeding, or intractable itching (already present in this case) 1, 4
• BSA >5% 1, 4
• Inadequate response to topical therapy after appropriate trial 1, 3
• Significant quality of life impairment 3, 2

Second-Line Treatment Options

If topical therapy proves insufficient:

Phototherapy (preferred second-line):

• Narrowband UVB phototherapy is the most effective and safest phototherapy option 1, 4
• Avoid commercial sunbeds as they emit primarily UVA and are rarely effective 3

Traditional systemic agents (second-line for moderate-to-severe disease):

• Methotrexate: Requires regular monitoring of complete blood count, liver function, and serum creatinine 2, 4
• Cyclosporine: Requires blood pressure, renal function, and lipid monitoring 2, 4
• Acitretin: Particularly useful for erythrodermic or pustular variants 1

Third-Line Biologic Therapy

For severe disease or inadequate response to conventional therapy:

TNF inhibitors are highly effective:

• Etanercept: Start 50mg twice weekly for 12 weeks, then maintenance 50mg weekly 1, 5
• At 3 months, 47% of patients achieve PASI 75 (75% improvement) with 50mg twice weekly dosing 5
• IL-17 and IL-23 inhibitors are also third-line options for refractory disease 1, 4

Critical Precautions and Monitoring

Avoid these common pitfalls:

• Never use systemic corticosteroids as they cause severe disease flare during taper 2, 4
• Discontinue triggering medications: Beta-blockers, NSAIDs, lithium, chloroquine, and mepacrine can precipitate or worsen psoriasis 1, 3, 2
• Counsel on alcohol avoidance as it may worsen disease 3, 2
• Long-term potent topical corticosteroids cause skin atrophy, striae, and telangiectasia 2, 4

Combination Therapy Strategies

To augment biologic efficacy if needed:

• Adding ultra-high potency (Class I) topical corticosteroid to etanercept for 12 weeks enhances response 4
• Adding calcipotriene/betamethasone to adalimumab accelerates plaque clearance 4
• Etanercept may be combined with narrowband UVB phototherapy 1

Follow-Up and Long-Term Management

Psoriasis is a chronic relapsing condition requiring ongoing management:

• Relapses are difficult to predict and cannot be prevented with topical agents alone 1, 3
• Regular follow-up is essential to assess treatment response and adjust therapy 3
• Patients with severe psoriasis requiring systemic agents should be under continuing dermatologist supervision due to potential toxicity 1