What are the treatment options for a psoriasis rash?

Treatment for Psoriasis Rash

Initial Treatment Approach

For mild psoriasis (<5% body surface area), start with topical corticosteroids (moderate to high potency, classes 2-5) combined with vitamin D analogs for maximum efficacy. 1, 2

Topical Therapy for Mild Disease

First-line topical agents:

• Combination therapy with topical corticosteroids plus vitamin D analogs (calcipotriene/calcipotriol) provides synergistic effects and superior efficacy compared to monotherapy 1, 2, 3
• Apply moderate to high potency corticosteroids (classes 2-5) for maximum 4 weeks on body plaques, avoiding intertriginous areas 2
• Use the fixed combination product of calcipotriene/betamethasone dipropionate for convenience and enhanced adherence 1, 3

Maintenance strategy:

• Switch to weekend-only corticosteroid application while using vitamin D analogs on weekdays to prevent tachyphylaxis and minimize side effects 2
• Rotate to alternative topical agents annually, as patients who fail one agent may respond to another 4

Site-specific modifications:

• For facial and intertriginous psoriasis, use low-potency corticosteroids or topical calcineurin inhibitors (tacrolimus 0.1%) to avoid skin atrophy 1, 2
• For scalp psoriasis, use high-potency topical corticosteroids (classes 1-7) or calcipotriene foam for 4-12 weeks 1, 2

Alternative Topical Agents

Coal tar preparations:

• Start with 0.5-1.0% crude coal tar in petroleum jelly, increasing every few days to maximum 10% 4
• Crude tar extracts are messier but more effective than refined products 4
• Coal tar is extremely safe for long-term use 4

Dithranol (anthralin):

• Begin at 0.1-0.25% concentration and increase in doubling concentrations as tolerated 4
• Use short-contact mode (15-45 minutes daily) to minimize irritancy and staining 4
• Avoid on sensitive areas (face, flexures, genitalia) 4

Tazarotene (topical retinoid):

• Combine with moderate to high potency corticosteroids to reduce irritation while enhancing efficacy 2, 3

Critical Safety Guidelines for Topical Corticosteroids

• Require regular clinical review with no unsupervised repeat prescriptions 4, 2
• Limit to maximum 100g of moderately potent preparation per month 4
• Very potent (class 1) or potent (class 2) preparations require dermatological supervision 4
• Plan annual periods using alternative treatments to prevent long-term complications 4, 2

Treatment for Moderate-to-Severe Psoriasis

For moderate-to-severe psoriasis (≥5% BSA) or symptomatic disease with pain/bleeding/itching regardless of BSA, escalate to phototherapy as first-line systemic treatment. 1, 3

Phototherapy Options

• Narrowband UVB phototherapy is the preferred first-line treatment for moderate-to-severe disease 4, 1, 3
• PUVA (psoralens plus UVA) is the least toxic systemic option and generally considered first-choice systemic treatment 4
• Treatments should be given no more frequently than every 48 hours, with courses lasting 8-10 weeks 4
• Avoid commercial sunbeds as they emit only UVA, are rarely effective, and may cause premature skin aging 4, 3

Traditional Systemic Agents (Second-Line)

When phototherapy fails or is impractical:

• Methotrexate, cyclosporine, or acitretin are second-line options requiring dermatologist supervision 1, 3
• All systemic agents require careful monitoring due to potential toxicity 4
• Methotrexate requires regular monitoring of complete blood count, liver function, and serum creatinine 3
• Cyclosporine requires monitoring of blood pressure, renal function, and lipid profile 3

Biologic Agents (Third-Line)

For inadequate response to traditional systemic agents:

• IL-17 inhibitors, IL-23 inhibitors, and IL-12/23 inhibitors are third-line options 1, 3
• TNF inhibitors like adalimumab are FDA-approved for moderate to severe chronic plaque psoriasis in adults who are candidates for systemic therapy or phototherapy 5
• Biologics can be combined with topical corticosteroids or calcipotriene to accelerate clearance 3

Rotational Therapy Strategy

• Rotate between treatment modalities every 1-2 years to minimize cumulative toxicity of individual treatments 1, 6
• This approach allows 4-5 years before returning to the first therapy, reducing long-term adverse effects 6

Special Psoriasis Types

Guttate psoriasis:

• Treat associated streptococcal infection with phenoxymethylpenicillin or erythromycin 4
• Consider tonsillectomy referral for repeated attacks after documented tonsillitis 4

Palmoplantar pustular psoriasis:

• Use moderately potent topical corticosteroids as first-line 4
• Consider systemic etretinate for refractory cases 4, 1

Generalized pustular or erythrodermic psoriasis:

• Requires hospital admission and systemic agents under dermatologist supervision 4

Psoriatic Arthritis Management

For joint involvement:

• NSAIDs for mild joint symptoms 1, 3
• DMARDs (methotrexate, sulfasalazine, leflunomide) for moderate-to-severe joint involvement 1, 3
• TNF inhibitors like adalimumab for inadequate response to at least one DMARD 1, 3, 5

Critical Pitfalls to Avoid

Medications that worsen psoriasis:

• Absolutely avoid systemic corticosteroids as they cause severe disease flare during taper 1, 2, 3
• Avoid or use caution with alcohol, beta-blockers, NSAIDs, lithium, chloroquine, and mepacrine 4, 2
• Lithium, chloroquine, and mepacrine can cause life-threatening psoriasis deterioration 4

Drug interactions:

• Do not use salicylic acid simultaneously with calcipotriol as acidic pH inactivates calcipotriol 2
• Apply vitamin D analogs after phototherapy to avoid inactivation 1

Pregnancy considerations:

• All commonly used systemic agents are absolutely contraindicated in pregnancy 4, 3
• Women of childbearing age require counseling and contraception before systemic therapy 4

Long-term corticosteroid complications:

• Prolonged use of potent topical corticosteroids causes skin atrophy, striae, and telangiectasia 1, 3
• Perceived tachyphylaxis is often due to poor adherence rather than receptor downregulation 2

When to Refer to Dermatology

• Patients requiring systemic agents need dermatologist supervision due to medication toxicity 4
• Use of very potent (class 1) or potent (class 2) topical corticosteroids requires dermatological oversight 4
• Generalized pustular or erythrodermic psoriasis requires immediate specialist referral 4