What is the best treatment approach for a patient with a potential diagnosis of psoriasis or nummular eczema, who also has hypertension and prediabetes?

Distinguishing Psoriasis from Nummular Eczema and Treatment Approach in a Patient with Hypertension and Prediabetes

For this patient with hypertension and prediabetes, accurate diagnosis is critical because if psoriasis is confirmed, you must screen aggressively for cardiovascular risk factors and avoid certain systemic therapies that worsen metabolic comorbidities, while if nummular eczema is diagnosed, high-potency topical corticosteroids are first-line without the same systemic concerns. 1, 2

Diagnostic Differentiation

Clinical Features of Psoriasis

• Plaque characteristics: Well-demarcated, erythematous plaques with silvery-white scale, typically symmetrically distributed on extensor surfaces (elbows, knees), scalp, and lower back 3
• Nail changes: Pitting, onycholysis, oil spots, and subungual hyperkeratosis are highly specific for psoriasis and absent in nummular eczema 3
• Auspitz sign: Pinpoint bleeding when scale is removed (not seen in nummular eczema) 3
• Distribution pattern: Favors extensor surfaces, scalp, and areas of trauma (Koebner phenomenon) 3

Clinical Features of Nummular Eczema

• Lesion morphology: Sharply defined, coin-shaped (1-10 cm diameter), erythematous, eczematous plaques that are intensely pruritic 4
• Distribution: Predominantly lower limbs, then upper limbs; rarely involves scalp or nails 4
• Skin background: Diffusely dry skin (xerosis) is characteristic 4
• Symmetry: Multiple, symmetrically distributed lesions 4

Diagnostic Testing

• Potassium hydroxide (KOH) preparation: Mandatory to exclude tinea corporis, which can mimic both conditions 4
• Patch testing: Consider if nummular eczema is chronic and recalcitrant, as contact allergy is common 4
• Skin biopsy: Reserve for atypical presentations; generally not necessary for classic presentations 4

Critical Comorbidity Management for Psoriasis Patients

Cardiovascular Risk Assessment Requirements

All patients with confirmed psoriasis require immediate cardiovascular risk screening including blood pressure, fasting glucose or hemoglobin A1C, and lipid panel. 1, 2

• Risk multiplication factor: Apply a 1.5 multiplication factor to cardiovascular risk scores if the patient has >10% body surface area involvement or is a candidate for systemic/phototherapy 1, 2
• Screening frequency for hypertension: Yearly for age ≥40 years or those with blood pressure 130-139/85-89 mmHg, overweight/obesity 1
• Screening frequency for diabetes: Every 3 years for adults aged 40-70 years with BMI ≥25 kg/m² 1

Metabolic Syndrome Association

• Psoriasis patients have significantly elevated risk of metabolic syndrome (pooled adjusted OR 2.26,95% CI 1.70-3.01) 1
• Individual components are more common in psoriasis: hypertension (31% vs 28%; OR 1.20), elevated glucose (22% vs 16%; OR 1.44), obesity (38% vs 31%; OR 1.38) 1

Treatment Algorithm for Psoriasis with Hypertension and Prediabetes

Mild Psoriasis (<3% Body Surface Area)

First-line: Topical combination therapy

• Calcipotriene/betamethasone dipropionate: Most effective first-line treatment, achieving clear/almost clear status in 40.9% at 8 weeks 5
• Duration: 4-12 weeks for scalp; similar duration for body 5
• Clobetasol propionate: Alternative high-potency topical corticosteroid for 2-week treatment periods 6

Moderate-to-Severe Psoriasis (≥3% Body Surface Area)

Critical contraindication: Avoid TNF inhibitors if any degree of heart failure exists, as they increase mortality in NYHA class III-IV heart failure. 2

Preferred Systemic Options (in order of preference):

1. IL-17 inhibitors (secukinumab, ixekizumab, brodalumab)

   • No cardiac contraindications unlike TNF inhibitors 2
   • Highly effective for moderate-to-severe psoriasis 2, 3
   • Also effective for psoriatic arthritis if present 3

2. IL-12/23 inhibitor (ustekinumab)

   • Safe in heart failure (no TNF-related cardiac risk) 2
   • Less frequent dosing (every 12 weeks after loading) 2, 3
   • Appropriate when TNF inhibitors are contraindicated 2

3. IL-23 p19 inhibitors (guselkumab, tildrakizumab, risankizumab)

   • Newer agents with excellent efficacy 3
   • No cardiac contraindications 3

4. Narrowband UVB phototherapy

   • Effective, cost-effective, lacks systemic toxicities 1
   • Requires multiple visits (significant time commitment) 2
   • Particularly useful when systemic therapy is contraindicated 1

Systemic Agents to Use with Extreme Caution:

Cyclosporine (3-5 mg/kg/day)

• Major concern: Commonly causes new-onset hypertension or worsens pre-existing hypertension 1
• Monitoring: Requires close blood pressure monitoring; amlodipine can reverse cyclosporine-induced hypertension 1
• Duration: Limit to short 3-4 month "interventional" courses 1
• Contraindications: Avoid in patients with renal disease 5

Methotrexate

• Metabolic effects: Can affect glucose metabolism; requires close monitoring in prediabetic patients 1
• Contraindications: Absolutely contraindicated with significant hepatic damage 5
• Monitoring: Requires liver function tests and renal function monitoring 5

Absolutely Avoid:

Systemic corticosteroids: Can precipitate erythrodermic or generalized pustular psoriasis upon withdrawal 2, 5

Treatment Algorithm for Nummular Eczema

First-Line Treatment

High or ultra-high potency topical corticosteroids are the mainstay of therapy. 4

• Clobetasol propionate 0.05% solution/cream: Apply to affected areas for 2-week treatment periods 6, 4
• Optimal skin care: Aggressive moisturization with emollients to address underlying xerosis 4
• Avoidance measures: Hot water baths, harsh soaps, and identifiable exacerbating factors 4

Expected Course

• Lesions typically clear over a few weeks with proper treatment 4
• Course can be chronic with relapses and remissions 4
• Maintenance moisturization reduces recurrence frequency 4

Lifestyle Modifications (Essential for Both Conditions, Especially Psoriasis)

Mandatory interventions to reduce cardiovascular risk and improve disease outcomes:

• Weight management: Dietary changes to achieve normal BMI through combined diet and exercise 2, 7
• Exercise regimen: 3 times weekly for 30 minutes or more 2
• Smoking cessation: Absolutely required, as smoking increases cardiovascular risk and worsens psoriasis 7
• Blood pressure control: Target based on cardiovascular risk calculated with 1.5 multiplication factor for psoriasis 1, 2, 7
• Lipid management: High-intensity statin therapy with target LDL-C <55 mg/dL with >50% reduction from baseline for high cardiovascular risk 7

Critical Pitfalls to Avoid

• Do not use beta-blockers long-term (≥6 years) in psoriasis patients: Associated with increased psoriasis risk (OR 1.39,95% CI 1.11-1.73), though short-term use is acceptable 1
• Do not assume all antihypertensives worsen psoriasis: Preponderance of evidence does not support avoiding specific antihypertensive classes in psoriasis 1
• Do not miss patch testing in chronic nummular eczema: Contact allergy is common and perpetuates the condition 4
• Do not forget KOH preparation: Tinea corporis can mimic both conditions and requires antifungal therapy 4
• Do not use TNF inhibitors (etanercept, adalimumab, infliximab) if any heart failure exists: Increased mortality risk in NYHA class III-IV 2

Coordination of Care

Cardiovascular risk management should be performed by either the primary care physician or the dermatologist, with close communication to ensure proper monitoring of blood glucose, hemoglobin A1C, blood pressure, and lipid levels. 1, 2