What is the approach for a full workup and treatment of psoriasis?

Full Workup for Psoriasis

Initial Clinical Assessment

Begin by establishing disease severity through body surface area (BSA) measurement, as this determines treatment pathway and risk stratification for future comorbidities. 1

Disease Classification

• Mild psoriasis: <5% BSA involvement 2, 3
• Moderate-to-severe psoriasis: ≥5% BSA OR involvement of vulnerable areas (face, genitals, hands, feet, scalp, intertriginous areas) regardless of total BSA 2, 3
• Symptomatic psoriasis: Consider systemic therapy even with limited BSA if patient experiences pain, bleeding, or severe itching 2, 3

Essential History Components

• Medication review: Identify drugs that precipitate or worsen psoriasis including beta-blockers, NSAIDs, lithium, chloroquine, mepacrine, and alcohol 1, 2
• Trigger assessment: Document history of trauma, obesity, infections (particularly streptococcal), stress, and recent medication changes 4
• Quality of life impact: Assess psychological distress and functional impairment, as this influences treatment decisions independent of physical extent 1, 2

Physical Examination Specifics

• Plaque characteristics: Document erythema, scaling, and induration on extensor surfaces (elbows, knees), scalp, and other affected areas 4, 5
• Nail examination: Look for pitting, onycholysis, oil spots, and subungual hyperkeratosis 1
• Joint assessment: Screen for psoriatic arthritis with focused musculoskeletal examination of peripheral joints and spine 1

Comorbidity Screening

Screen all patients with moderate-to-severe psoriasis for associated systemic conditions, as psoriasis is a multisystem inflammatory disorder. 1

Mandatory Screening

• Psoriatic arthritis: Ask about joint pain, stiffness, swelling, and dactylitis 1
• Cardiovascular disease: Assess for hypertension, hyperlipidemia, diabetes, obesity, and smoking history 1, 6
• Metabolic syndrome components: Screen for diabetes mellitus, obesity, and dyslipidemia 1, 6
• Celiac disease: In moderate-to-severe plaque psoriasis, inquire about gastrointestinal symptoms; if positive, obtain celiac antibodies and refer to gastroenterology 1
• Mental health: Screen for depression and anxiety given high prevalence in psoriasis patients 1, 6
• Inflammatory bowel disease: Ask about abdominal pain, diarrhea, and bloody stools 1

Laboratory Evaluation

• Baseline labs before systemic therapy: Complete blood count, comprehensive metabolic panel, liver function tests, renal function, lipid panel, fasting glucose or HbA1c 1, 7
• Tuberculosis screening: PPD or interferon-gamma release assay before initiating biologic therapy 8
• Hepatitis B and C screening: Before starting systemic or biologic therapy 8
• Pregnancy test: For women of childbearing age before systemic therapy 7

Treatment Algorithm by Disease Severity

Mild Psoriasis (<5% BSA)

Start with ultra-high potency (Class I) topical corticosteroids combined with vitamin D analogues for thick plaques on trunk and extremities. 1, 3, 7

First-Line Topical Therapy

• Ultra-high potency corticosteroids: Clobetasol propionate 0.05% or halobetasol propionate 0.05% for thick plaques 1, 3
• Combination therapy: Calcipotriene/betamethasone dipropionate to enhance efficacy and improve compliance 3, 7
• Low-potency corticosteroids: For facial and intertriginous areas to avoid skin atrophy 1, 3
• Maximum dosing: No more than 100g of moderately potent preparation per month 1, 3

Critical Safety Measures for Topical Corticosteroids

• Regular clinical review: No unsupervised repeat prescriptions 1, 3
• Rotational therapy: Periods each year using alternative treatments (coal tar, dithranol) to minimize cumulative toxicity 1, 7
• Avoid long-term potent steroids: Risk of skin atrophy, striae, and telangiectasia 2, 3

Alternative Topical Agents

• Coal tar: Start with 0.5-1.0% crude coal tar in petroleum jelly, increase to maximum 10% every few days 1
• Dithranol (anthralin): Effective but requires adequate patient education regarding staining and irritation 1
• Vitamin D analogues alone: Calcipotriene maximum 100g per week to avoid hypercalcemia 3

Moderate-to-Severe Psoriasis (≥5% BSA)

Advance to narrowband UVB phototherapy as first-line treatment for moderate-to-severe disease, with biologic agents recommended as first-line systemic option due to superior efficacy and acceptable safety profiles. 2, 7, 6

Phototherapy

• Narrowband UVB: First-line phototherapy, treatments no more frequently than every 48 hours 7
• Treatment course: 8-10 weeks duration 7
• Dose adjustment: Increase by 40% if no erythema, 20% if slight erythema, hold if more than slight erythema 7
• PUVA (psoralen plus UVA): Alternative for refractory cases 1, 9
• 308-nm excimer laser: For localized resistant areas 3

Traditional Systemic Agents (Second-Line)

• Methotrexate: Start 15 mg weekly, maximum 25-30 mg weekly; response within 2 weeks; requires baseline and regular liver function monitoring 7, 6
• Cyclosporine: 2.5-5 mg/kg daily; rapid response within 3 weeks; requires blood pressure and renal function monitoring 7, 6
• Acitretin: For pustular and erythrodermic variants; teratogenic with prolonged washout period 1, 6

Biologic Agents (First-Line Systemic Option)

The American Academy of Dermatology-National Psoriasis Foundation guidelines recommend biologics as first-line treatment for moderate-to-severe plaque psoriasis due to superior efficacy and acceptable safety profiles. 6

TNF-α Inhibitors

• Adalimumab: 80 mg initial dose, then 40 mg every other week starting one week after initial dose 8, 6
• Etanercept: 50 mg twice weekly for 3 months, then 50 mg weekly 4, 6
• Infliximab: 5 mg/kg IV at weeks 0,2,6, then every 8 weeks 4, 6

IL-12/23 Inhibitors

• Ustekinumab: For patients ≤100 kg: 45 mg at weeks 0 and 4, then every 12 weeks; for patients >100 kg: 90 mg at weeks 0 and 4, then every 12 weeks 10, 6

IL-17 Inhibitors

• Secukinumab, ixekizumab, brodalumab: Highly effective for moderate-to-severe plaque psoriasis 4, 6

IL-23 Inhibitors

• Guselkumab, tildrakizumab, risankizumab: Target p19 subunit of IL-23 with excellent efficacy 4, 6

Small Molecule Inhibitors

• Apremilast: Phosphodiesterase 4 inhibitor; oral option for patients who prefer non-injectable therapy 6, 5

Special Psoriasis Subtypes

Scalp Psoriasis

• First-line: Calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks 2, 3
• Refractory cases: Excimer laser therapy 3

Guttate Psoriasis

• Treatment: Low concentrations of tar and dithranol; narrowband UVB especially helpful 7
• Infection management: Investigate and treat streptococcal infection with phenoxymethylpenicillin or erythromycin 7

Facial and Intertriginous Psoriasis

• Low-potency corticosteroids: To avoid skin atrophy 1, 3
• Topical calcitriol: Less irritating than other vitamin D analogues for sensitive areas 3

Critical Safety Considerations

Absolute Contraindications

• Systemic corticosteroids: Avoid entirely as they cause severe disease flare during taper 2, 3
• All systemic agents in pregnancy: Absolutely contraindicated; ensure contraception in women of childbearing age 7

Pre-Biologic Screening

• Tuberculosis: PPD or interferon-gamma release assay mandatory before starting TNF inhibitors 8
• Hepatitis B: Screen and treat if positive before biologic initiation 8
• Fungal infection risk: Ask about residence in endemic areas (Ohio/Mississippi River valleys) for histoplasmosis, coccidioidomycosis, blastomycosis 8
• Malignancy history: Assess cancer risk, particularly lymphoma and skin cancers 8

Monitoring During Treatment

• Infection surveillance: Educate patients to report fever, persistent cough, weight loss, or new skin lesions immediately 8
• Skin cancer screening: Regular examination for basal cell and squamous cell carcinoma, especially with TNF inhibitors 8
• Hepatosplenic T-cell lymphoma risk: Particularly in young males on combination therapy with azathioprine or 6-mercaptopurine 8

Adjunctive Therapies

Evidence-Based Lifestyle Modifications

• Weight management: Maintain ideal body weight to improve disease severity 5, 11
• Smoking cessation: Avoid tobacco products 5
• Alcohol limitation: Reduce or eliminate alcohol consumption 1, 5
• Stress reduction: Mindfulness meditation and cognitive behavioral therapy improve psoriasis severity 1, 2

Alternative Medicine with Evidence

• Oral curcumin supplementation: May benefit as adjunctive therapy 1, 2
• Gluten-free diet: Only for patients with confirmed celiac disease; trial period of 3 months if celiac antibodies positive 1
• Hypnosis: Can be incorporated for highly hypnotizable patients with mild-to-moderate psoriasis 1

Therapies Without Sufficient Evidence

• Oral vitamin D supplementation: Does not directly improve disease activity at safe dosages 1
• Oral zinc supplementation: Does not improve PASI scores 1
• Cannabis and cannabinoids: Insufficient literature to justify use 1

Patient Education Essentials

Educate all patients and caregivers regarding disease etiology, natural history, triggers, potential comorbidities, treatment options with risk profiles, and lifestyle factors. 1

• Disease chronicity: Explain that psoriasis is lifelong with waxing and waning course; few spontaneous remissions occur 1
• Comorbidity awareness: Inform about increased cardiovascular, metabolic, and mental health risks 1
• Support resources: Direct to National Psoriasis Foundation (www.psoriasis.org) and International Federation for Psoriasis 1
• Vaccination timing: Complete all vaccines before starting biologic therapy; avoid live vaccines during treatment 8