What are the recommended biologic agents, dosing regimens, baseline infection screening, monitoring, and criteria for switching therapy for moderate‑to‑severe inflammatory skin diseases (psoriasis, atopic dermatitis, hidradenitis suppurativa, alopecia areata) in India?

Biologics in Dermatology in India

Eligibility Criteria for Biologic Therapy

Biologic therapy should be initiated only when patients meet strict dual criteria: DLQI >10 AND either PASI ≥10 or BSA >10%, plus documented failure, intolerance, or contraindication to BOTH methotrexate AND ciclosporin. 1

• Patients must have disease severity persisting for at least 6 months that has proven resistant to conventional treatment 1
• PUVA therapy failure, intolerance, or contraindication also qualifies as a prerequisite 1
• Never use biologics as first-line therapy without meeting these treatment-failure requirements 1

Earlier Initiation Scenarios

Consider biologics earlier in the treatment pathway when patients meet severity criteria AND have: 1

• Active psoriatic arthritis requiring treatment
• Rapidly relapsing disease
• Severe unstable life-threatening disease
• Clinically important drug-related toxicity risk from conventional agents
• Significant comorbidity precluding methotrexate or ciclosporin use

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Mandatory Pre-Treatment Screening

All patients must undergo comprehensive baseline screening before biologic initiation: 2

• Chemistry panel with liver function tests 2
• Complete blood count including platelet count 2
• Hepatitis B and C serology (mandatory for anti-TNF agents and itolizumab) 1
• Tuberculosis testing (mandatory for all TNF inhibitors due to reactivation risk) 3
• Pregnancy test for women of childbearing potential 2

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First-Line Biologic Agents for Psoriasis

TNF-α Inhibitors

Adalimumab is the preferred first-line biologic, particularly when psoriatic arthritis is present: 2

Agent	Dosing Regimen	Assessment Timepoint	Key Indications
Adalimumab	80 mg week 0,40 mg week 1, then 40 mg every other week SC	16 weeks [1]	First choice for psoriasis with psoriatic arthritis [2]
Etanercept	50 mg SC twice weekly for 12 weeks, then 50 mg once weekly	12 weeks [1]	Moderate-to-severe plaque psoriasis [1]
Infliximab	5 mg/kg IV at weeks 0,2,6, then every 8 weeks	10-14 weeks [1]	Severe psoriasis (PASI ≥20, DLQI ≥18); generalized pustular psoriasis [1]

Critical safety note: Interrupted infliximab therapy significantly increases infusion-reaction risk and worsens disease control 1

IL-12/23 Inhibitor

Ustekinumab is an alternative first-line option: 1

• 45 mg at weeks 0 and 4, then every 12 weeks for patients ≤100 kg
• 90 mg for patients >100 kg
• Assess response between weeks 16-28 1
• Consider when psoriatic arthritis is present (alongside adalimumab) 2

IL-17 Inhibitor

Secukinumab is positioned as second-tier after TNF-inhibitor failure: 1

• 300 mg SC weekly for first 4 weeks, then every 4 weeks
• Most commonly used biologic among Indian dermatologists in recent surveys 4

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Treatment Response Assessment

Success is defined as either PASI 75 OR PASI 50 plus DLQI improvement >5 points: 1

• Etanercept: Evaluate at 12 weeks 1
• Adalimumab: Evaluate at 16 weeks 1
• Infliximab: Evaluate at 10-14 weeks 1
• Ustekinumab: Evaluate between 16-28 weeks 1

If minimum response criteria are not met at the designated timepoint, switch to another biologic class immediately 1

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Switching Biologics After Treatment Failure

After First Biologic Failure

Switch to any currently licensed biologic, tailoring choice to patient-specific factors: 2

• Consider body weight (dose escalation may be needed in obesity, though not applicable to secukinumab or ixekizumab) 2
• Evaluate presence and phenotype of psoriatic arthritis (peripheral vs. axial disease influences choice) 2
• Review comorbid conditions, conception plans, and previous treatment outcomes 2

After TNF-Inhibitor Failure

IL-23 inhibitors (guselkumab, risankizumab) are the optimal next-line class after TNF-inhibitor failure 1

Dose Escalation Strategy

Consider dose escalation when inadequate primary response may be due to insufficient dosing (e.g., obesity or disease relapse during treatment cycle): 2

• Not applicable to secukinumab or ixekizumab 2
• Increases infection risk and may be off-license/unfunded 2

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Special Psoriasis Variants

Generalized Pustular Psoriasis

Infliximab demonstrates the strongest evidence for rapid response and complete clearance: 1

• Etanercept 50 mg twice weekly also shows sustained efficacy up to 48 weeks 1

Acropustulosis of Hallopeau

TNF antagonists (etanercept, infliximab, adalimumab) provide significant benefit when conventional therapy fails 1

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Atopic Dermatitis

Dupilumab is the only FDA-approved biologic for moderate-to-severe atopic dermatitis in patients ≥6 years: 5

• Consistent long-term efficacy and safety data 5
• Targets IL-4 and IL-13 pathways 5

Emerging agents in phase 2/3 trials include lebrikizumab, tralokinumab, nemolizumab, tezepelumab, and ISB 830 5

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Hidradenitis Suppurativa & Alopecia Areata

For hidradenitis suppurativa, TNF-alpha inhibitors are used off-label with limited data restricted to case series 6

For alopecia areata, current evidence does not support specific biologic recommendations; JAK inhibitors show promise in case reports but lack robust data 1

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Monitoring During Biologic Therapy

Patients require periodic re-evaluation for infection and malignancy: 2

• Hold biologic therapy if serious infection develops (requiring antibiotic therapy) until infection resolves 2
• Treatment is contraindicated in patients with active, serious infections 2
• Avoid live vaccines in infants born to mothers taking biologics beyond 16 weeks' gestation 2

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Pregnancy and Conception

Advise women of childbearing potential to use effective contraception and discuss conception plans: 2

• Most biologics are pregnancy category B (efalizumab is category C) 2
• Maternal IgG (and therefore biologics) is actively transferred to the fetus during second and third trimesters 2
• Discuss risks/benefits of continuing vs. stopping therapy on a case-by-case basis 2
• Consider the risk of severe/unstable psoriasis if therapy is stopped 2

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Cardiovascular Benefits of TNF Inhibitors

TNF inhibitors provide significant cardioprotective effects in psoriasis patients: 3

• Reduce major adverse cardiovascular events (MACE) with hazard ratio 0.50 (95% CI 0.32-0.79, P=0.003) 3
• Myocardial infarction risk reduced by 50% compared to topical agents 3
• Cumulative 24-month exposure associated with 11% cardiovascular event risk reduction 3

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Contraindications and Special Precautions

Absolute contraindications: 3

• Active tuberculosis or serious infections
• First-degree relatives with multiple sclerosis (for TNF inhibitors)

Use with caution: 3

• Congestive heart failure (reports of new onset and worsening CHF with TNF inhibitors)
• History of lymphoma or nonmelanoma skin cancer 7

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Practical Considerations in India

Cost is the major barrier to biologic use among Indian dermatologists: 4

• 70% of surveyed dermatologists use biologics, but majority prescribe <2 cases per month 4
• Secukinumab is most commonly used, followed by etanercept 4
• Factors determining choice: convenience, cost, previous experience, comorbid conditions, expert recommendations 4

All biologic therapy must be initiated and supervised by specialist physicians experienced in psoriasis diagnosis and treatment 1