Dermatology/Systemic immunomodulator / biologic

Systemics & biologics (psoriasis/eczema)

also: methotrexate · ciclosporin · adalimumab · secukinumab · dupilumab · biologics

Overview

Systemic therapy for severe psoriasis and atopic eczema when topicals/phototherapy fail. Biologics target specific cytokines; screen for infection/TB first.

Mechanism

Conventional: methotrexate (antifolate, antiproliferative/immunosuppressive), ciclosporin (calcineurin inhibitor), apremilast (PDE4 inhibitor). Biologics neutralise the cytokines driving disease: TNF-α (adalimumab/etanercept/infliximab), IL-17 (secukinumab/ixekizumab), IL-23 (guselkumab/risankizumab), IL-12/23 (ustekinumab); IL-4/13 (dupilumab — eczema).

Indications

Moderate–severe plaque psoriasis (+ psoriatic arthritis)
Severe atopic eczema (dupilumab, JAK inhibitors)

The agents

Methotrexateantifolate

WEEKLY + folic acid

Cross-references the rheumatology/cross-cutting card; pneumonitis, myelosuppression, hepatotoxicity.

Ciclosporincalcineurin inhibitor

Rapid; nephrotoxic, hypertension, gum hyperplasia — short-term.

TNF inhibitors (adalimumab/etanercept/infliximab)biologic

SC/IV

TB reactivation — screen + treat latent TB first.

IL-17/IL-23 inhibitors (secukinumab/guselkumab/ustekinumab)biologic

IL-17 can flare IBD / cause candidiasis.

DupilumabIL-4/13 biologic

Severe atopic eczema; conjunctivitis.

Adverse effects

Serious infection / immunosuppressionserious

TB reactivation (anti-TNF)serious

Screen (IGRA/CXR) before starting.

Methotrexate: myelosuppression, hepatotoxicity, pneumonitisserious

Ciclosporin: nephrotoxicity, hypertension, gingival hyperplasiaserious

Injection-site / infusion reactionscommon

Cautions & contraindications

Active serious infection / untreated latent TBall

Methotrexate in pregnancy & significant liver diseasepregnancy

Teratogen/abortifacient.

Live vaccines with biologics / immunosuppressionall

Interactions

Methotrexate + trimethoprim/NSAIDs → marrow toxicity
Live vaccines contraindicated

Monitoring & kinetics

Pre-biologic: TB + hepatitis B/C + HIV screen,Methotrexate: FBC/U&E/LFTs,Ciclosporin: renal function + BP

MTX weekly oral/SC; biologics SC/IV at intervals.

Source: NICE CG153 — Psoriasis · BNF — Drugs affecting the immune response