30-second key takeaways

Key Points

Source: a JAAD 2026 systematic review (Duong et al) screened 4,503 articles and analyzed 73, applying USPSTF evidence grades to routine screening/monitoring for psoriasis biologics.
TNF-α inhibitors (adalimumab / infliximab / etanercept / certolizumab): initial and annual TB screening remain warranted (grade B); chronic HBV carriers may benefit from HBV viral load and LFT monitoring (grade C).
IL-17 inhibitors (secukinumab / ixekizumab / brodalumab / bimekizumab): no routine bloods needed; ask about oral candidiasis (white plaques, dysphagia) and bowel symptoms at each visit (both grade C).
IL-12/23 (ustekinumab) and IL-23 p19 (guselkumab / risankizumab / tildrakizumab): nearly every routine screen earns grade D (evidence shows no benefit) — TB, HBV, HCV, CBC, CMP, lipids, ANA, COVID-19, malignancy, CHF, candida, IBD, and pregnancy screening are not recommended.
Across all classes, grade D applies to HCV, CBC, CMP, lipids/glucose, ANA, COVID-19, malignancy, full-body skin exam, CHF, and pregnancy testing (absent specific clinical indication). HIV: grade I (insufficient evidence).
Evidence grades ≠ NHI policy: Taiwan NHI still requires baseline TB (IGRA or X-ray), HBV, HCV, HIV, CBC, and CMP for biologic applications, with 6-monthly renewal review. Some testing reflects administrative process rather than direct clinical benefit.
Limitations: USPSTF grades do not consider cost; most evidence comes from cohort studies and post-hoc safety pools of trials rather than RCTs designed to compare "screen vs no-screen"; rheumatology/GI patients on concomitant MTX may inflate TNF-α HBV reactivation rates seen in some series.

Why this question matters

Biologics are the workhorse of moderate-to-severe psoriasis. Taiwan NHI currently lists more than 10 agents across four mechanism classes — TNF-α (etanercept, adalimumab, infliximab, certolizumab), IL-12/23 (ustekinumab), IL-17 (secukinumab, ixekizumab, brodalumab, bimekizumab), and IL-23 p19 (guselkumab, risankizumab, tildrakizumab). Once a patient reaches this tier, the long-standing convention has been "full baseline labs, then repeat panels every 6–12 months."

That convention grew out of early TNF-α-era safety signals: TB reactivation, HBV reactivation, CHF worsening. When IL-17 and IL-23 inhibitors arrived with different mechanisms — and different safety profiles — the screening checklists from AAD, BAD, EADV, and JDA mostly carried over unchanged. The result: patients undergo routine semi-annual or annual labs, but most abnormalities are false positives, transient, or do not change management. Duong et al's JAAD 2026 systematic review asks the core question: which tests actually help, and which persist by inertia?

Patient FAQs

Q1: Do I need annual blood tests just because I'm on a biologic?

It depends on which class you take. TNF-α inhibitors (adalimumab, infliximab, etanercept, certolizumab) still warrant annual TB screening (IGRA or chest X-ray), plus HBV viral-load and liver-function follow-up if you are a chronic HBV carrier. IL-17 inhibitors (secukinumab, ixekizumab, brodalumab, bimekizumab) and IL-23 inhibitors (guselkumab, risankizumab, tildrakizumab, ustekinumab) generally do not require routine bloods. However, Taiwan NHI applications and 6-monthly renewal reviews still require multiple baseline and follow-up labs — this is administrative policy, not always clinical necessity.

Q2: So why did I get blood drawn every year before?

Two reasons. Historical inertia: the early-TNF-α-era checklist was copied wholesale to IL-17 and IL-23 inhibitors despite different safety profiles. Administrative process: Taiwan NHI PASS pre-authorization and 6-monthly renewal still require CBC, LFTs, lipids, HBV, HCV, HIV, and TB screening (IGRA or chest X-ray) as documentation. Many clinicians order full panels habitually to avoid missing items.

Q3: I'm on an IL-17 inhibitor — why does my doctor keep asking about my mouth?

IL-17 plays a key role in antifungal immunity, especially against Candida. Blocking it raises the risk of oral/esophageal candidiasis. Bimekizumab carries the highest risk (3-year cumulative oral candidiasis ~21.8%, most mild–moderate and decreasing with continued exposure); secukinumab, ixekizumab, and brodalumab long-term studies also show elevated rates. That's why your doctor asks about white plaques in the mouth and painful or sticky swallowing — the two classic clues. If present, examine and treat with antifungals; routine blood tests are not needed for prevention.

Q4: Why does my IL-17 inhibitor doctor ask about diarrhea?

IL-17 inhibitors carry a weak but real signal for inflammatory bowel disease (Crohn's disease, ulcerative colitis). Pivotal trials and long-term observational data show slightly higher IBD rates in IL-17-treated arms vs placebo (still low, often ≤ 0.2/100 patient-years). Bimekizumab also has a small number of cases considered treatment-related. That's why visits ask about new abdominal pain, chronic diarrhea, blood in stool, or unintended weight loss. If present, gastroenterology workup is warranted; routine stool studies or screening colonoscopy are not. TNF-α inhibitors and IL-23 inhibitors do not show this signal.

Q5: I'm a chronic HBV carrier — can I receive biologics?

Mostly yes, with caveats. Resolved HBV (HBsAg–, HBsAb+, HBcAb+) and occult HBV (HBsAg–, HBsAb–, HBcAb+) patients usually do well on adalimumab, etanercept, ustekinumab, risankizumab, tildrakizumab, ixekizumab, secukinumab, or brodalumab even without antiviral prophylaxis. Chronic HBV (HBsAg+, HBcAb+) carries the highest reactivation risk — about 7.7% with antiviral prophylaxis (entecavir or tenofovir) vs 26% without. Chronic carriers should be co-managed with hepatology/infectious disease before biologic initiation, with viral load and LFT monitoring during treatment.

Q6: What about HCV, HIV, heart failure, malignancy?

HCV: biologic-related HCV reactivation is rare and indistinguishable from natural HCV viral fluctuations; routine follow-up is unnecessary absent symptoms (grade D). HIV: in well-controlled HIV patients receiving biologics alongside HAART, viral load tracks the matched control group; data are sparse (grade I, insufficient evidence). CHF: infliximab early trials showed worsening CHF, so moderate-to-severe CHF patients traditionally avoid TNF-α; other classes show no such signal, and routine echocardiogram screening provides no benefit (grade D). Malignancy: long-term registries (PSOLAR and others) show comparable cancer rates in biologic-treated psoriasis vs the general psoriasis population. Outside of PUVA history or age-appropriate cancer screening, additional surveillance is not warranted (grade D).

Q7: Should I stop my biologic before pregnancy? Routine pregnancy testing?

The review concludes routine pregnancy testing is not necessary (grade D). PSOLAR registry, case series, and incidentally pregnant trial subjects show adalimumab, infliximab, etanercept, ustekinumab, and secukinumab first-trimester exposures generally yield normal live births, with congenital anomaly rates comparable to non-biologic-treated psoriasis. Certolizumab pegol lacks an Fc region, has minimal placental transfer, and has the most reassuring pregnancy data — making it the preferred biologic when patients are planning conception. Whether, when, and which biologic to use during family planning still requires joint dermatology–obstetrics decision-making.

Which class are you on? One-page summary

Biologic class	Examples (Taiwan brand names)	What's worth doing (evidence-supported)	What's unnecessary (grade D)
TNF-α inhibitors	Adalimumab (Humira), infliximab (Remicade), etanercept (Enbrel), certolizumab pegol (Cimzia)	Initial + annual TB screening (B); consider HBV viral load + LFT monitoring if chronic HBsAg+ (C)	HCV, HIV, CBC, CMP, lipids, ANA, COVID, malignancy, full-body skin exam, CHF, pregnancy (unless specifically indicated)
IL-12/23 inhibitor	Ustekinumab (Stelara)	No routine required screening; tailor to individual risk (TB exposure, HBV carrier, etc.)	TB, HBV, HCV, CBC, CMP, lipids, ANA, COVID, malignancy, CHF, candida, IBD, pregnancy (all grade D)
IL-23 p19 inhibitors	Guselkumab (Tremfya), risankizumab (Skyrizi), tildrakizumab (Ilumya)	Same as above: no routine required screening; tailor to individual risk	Same as IL-12/23 (nearly all grade D)
IL-17 inhibitors	Secukinumab (Cosentyx), ixekizumab (Taltz), brodalumab (Lumicef), bimekizumab (Bimzelx)	Ask about oral candidiasis (white plaques, dysphagia) and bowel symptoms at visits (C); no routine bloods needed	TB, HBV, HCV, CBC, CMP, lipids, ANA, COVID, malignancy, CHF, pregnancy (grade D)

Figure 1. USPSTF evidence-grade heatmap. Initial and annual TB screens for TNF-α inhibitors are among the few grade B recommendations; HBV is grade C. IL-17 inhibitors — clinical inquiry about oral candidiasis and bowel symptoms is grade C. IL-12/23 (ustekinumab) and IL-23 p19 (guselkumab / risankizumab / tildrakizumab) earn grade D for nearly all routine screening. HCV, CBC, CMP, lipids, ANA, COVID, malignancy, CHF, and pregnancy testing are grade D across all classes; HIV is grade I (insufficient evidence).

Advanced: methodology and the USPSTF grading framework

For residents / methodology-interested readers

Duong et al searched PubMed and Cochrane using "psoriasis", "safety", "monitoring", "screening", "risk", "testing", plus generic and brand names of each biologic. English-language articles from 2014-01-01 to 2023-11-01 were eligible; case reports, animal studies, multi-agent regimens, and non-plaque psoriasis indications were excluded. Two reviewers screened titles and abstracts in Covidence, with full-text review for inclusion. 4,503 → 191 → 73 articles entered qualitative analysis.

USPSTF (US Preventive Services Task Force) grades: A = strongly recommend (good evidence, substantial net benefit); B = recommend (slightly lower evidence or magnitude than A); C = no blanket recommendation for or against, case-by-case (small net benefit); D = recommend against (good or fair evidence that net benefit is zero or negative); I = insufficient evidence. USPSTF methodology does not factor in cost, but it does evaluate the downstream harms of false positives — anxiety, additional invasive workup, unnecessary prophylactic treatment.

Tuberculosis screening — in depth

Disseminated TB within 15 weeks of biologic exposure carries about 7% mortality (Snast 2019 systematic review). Taiwan is a moderate-prevalence area, so pre-treatment TB screening is justified. IGRAs (e.g., QuantiFERON) outperform tuberculin skin testing in sensitivity, with comparable specificity and no BCG interference (Jonas 2023, JAMA), making them generally preferred.

TNF-α inhibitors: most latent TB reactivations and new TB cases occur in this class, sometimes despite prophylaxis. Initial and annual screening is warranted (grade B). IL-17, IL-12/23, IL-23 inhibitors: multiple studies show extremely low reactivation risk, even in untreated latent TB (Torres 2024; Nogueira 2021; Fowler 2020; Manzanares 2024). Duong et al thus recommend against routine initial or annual TB screening for these classes (grade D) — assuming no exposure history. Patients with TB exposure or symptoms (unexplained weight loss, cough, fever) should still be evaluated. Phase 3 trials include TB screening largely by historical convention rather than from a real mechanistic concern.

Hepatitis B (HBV) — in depth

Taiwan is HBV-endemic (adult HBsAg prevalence ~5–10%), making this question even more salient than in Western populations. Duong et al's evidence stratifies three serologic states:

HBV status	Reactivation rate on biologics	Practical recommendation
Resolved (HBsAg-, HBsAb+, HBcAb+)	Very low; cohort studies (adalimumab, etanercept, ustekinumab, risankizumab, tildrakizumab, ixekizumab, secukinumab, brodalumab) show rare reactivation even without antiviral prophylaxis	Treat with confidence; record baseline HBsAg / HBsAb / HBcAb once
Occult (HBsAg-, HBsAb-, HBcAb+)	Low; existing data suggest safe use without antiviral prophylaxis	Coordinate with hepatology; monitor periodically during treatment
Chronic (HBsAg+, HBcAb+)	~26% without prophylaxis; ~7.7% with (entecavir / tenofovir); TNF-α inhibitors carry the highest risk	Co-manage with hepatology / infectious disease: start antiviral prophylaxis + monitor viral load + LFTs

Key detail: chronic carriers on TNF-α with antiviral prophylaxis still have reactivation cases, but no reactivations have been reported for secukinumab + prophylaxis or ustekinumab + prophylaxis in psoriasis (Snast 2017; Chiu 2018). Duong et al give TNF-α a grade C for baseline HBV screening plus viral-load + LFT monitoring in chronic carriers; IL-17, IL-12/23, and IL-23 receive grade D (no routine HBV testing). Taiwan reality: with HBsAg prevalence of 5–10% and many patients already aware of their carrier status, Taiwan NHI biologic applications and renewals still record HBV serology as part of pretreatment safety assessment — different from Duong's "all classes" recommendation, but justified by local epidemiology.

Figure 2. HBV reactivation risk in chronic HBV (HBsAg+) psoriasis patients on biologics. The largest dataset is for TNF-α inhibitors: ~26% reactivation without prophylaxis, falling to ~7.7% with entecavir or tenofovir (Snast 2017). No reactivations have been reported with secukinumab + prophylaxis or ustekinumab + prophylaxis in published series. Implication: chronic carriers on TNF-α must receive concomitant antiviral prophylaxis; switching to IL-17 or IL-12/23 + prophylaxis is a safer alternative.

Other routine labs (HCV / HIV / CBC / CMP / lipids / ANA)

HCV: grade D for all classes. Biologic-related HCV reactivation is rare and overlaps with natural HCV viral fluctuation.
HIV: grade I (insufficient evidence) across classes. Well-controlled HIV patients on biologics show viral-load variability comparable to HAART-matched controls (Xu 2023, JEADV).
CBC / CMP: grade D across classes. Trial-reported cytopenias and hepatic enzyme elevations are mostly transient and rarely lead to discontinuation; no new safety signals from long- or short-term studies.
Lipids / glucose: grade D. Psoriasis patients on TNF-α, secukinumab, ixekizumab, or tildrakizumab show no substantial lipid shifts (Menter 2020; Wu 2014; Gerdes 2020); routine lipid monitoring is uninformative.
ANA: grade D. Drug-induced lupus is rare in biologic-treated psoriasis; routine ANA screening provides no benefit.
Malignancy: grade D. Long-term registries (PSOLAR, OBSERVE-5, ESPRIT) show comparable cancer rates between biologic-treated and non-biologic psoriasis populations; CTCL association is weak (Davis 2024). Age-appropriate cancer screening proceeds as usual.
CHF: grade D for routine screening. Clinically, TNF-α is still avoided in moderate-severe CHF patients (infliximab early-trial signal of worsening CHF).
COVID-19 / pregnancy: grade D. Biologics do not increase COVID-19 severity or mortality (TNF-α may even be protective); pre-treatment COVID screening offers no benefit. Routine pregnancy testing also not warranted.

IL-17 inhibitors: candidiasis and IBD monitoring

Oral / esophageal candidiasis: IL-17 plays a major role in antifungal (especially mucosal Candida) immunity; blocking it raises infection risk. Pivotal trials and long-term safety pools show higher Candida rates in secukinumab, ixekizumab, brodalumab, and bimekizumab arms vs comparators.

Bimekizumab carries the highest risk: BE READY / BE VIVID 16-week oral candidiasis rate 6–11%; 3-year cumulative 21.8% (Gordon 2024, BJD). Most were mild–moderate; incidence decreased with longer exposure and with q8w (vs q4w) maintenance dosing.
Deep fungal infections: no increase across any biologic class (Lee 2020, Cutis).
IL-23 inhibitors (guselkumab, risankizumab, tildrakizumab): Candida rates comparable to controls in pivotal trials and long-term follow-up (grade D, no screening needed).

Practical: during IL-17 therapy, monitor by oral inspection or asking about white plaques, dysphagia, throat burning at each visit (grade C). Routine endoscopy or skin/genital fungal cultures in asymptomatic patients are not recommended (grade D).

IBD: weak association with IL-17 inhibitors. Pivotal trial induction phases showed a few IBD cases on secukinumab and ixekizumab vs none in placebo; ixekizumab maintenance added 7 more (Gordon 2016). Long-term observational rates are mostly ≤ 0.2/100 PY, comparable to general psoriasis populations (Langley 2023; Griffiths 2022). Bimekizumab has a small number of cases considered treatment-related; brodalumab and IL-23 inhibitors do not show this signal. Etanercept in autoimmune disease patients is significantly associated with new-onset Crohn's disease and ulcerative colitis (Korzenik 2019).

Practical: at initiation and each follow-up on IL-17 inhibitors, ask about abdominal pain, chronic diarrhea, blood in stool, weight loss, and any IBD history (grade C). Routine fecal markers (e.g., calprotectin), fecal occult blood, or screening colonoscopy are not warranted (grade D).

Figure 3. Screening and clinic-monitoring decision tree by biologic class. TNF-α is the only class requiring annual TB screening; chronic HBV carriers need antiviral prophylaxis plus viral-load and LFT monitoring. IL-12/23 and IL-23 p19 earn mostly grade D under USPSTF, though Taiwan NHI still requires baseline documentation. IL-17 monitoring centers on symptom inquiry for candidiasis and IBD at every visit.

Taiwan NHI : gap between evidence and policy

Taiwan-specific reality

The USPSTF grades reflect evidence of clinical benefit, not the requirements of Taiwan's reimbursement workflow. NHI biologic PASS pre-authorization and 6-monthly renewals still require:

TB screening (IGRA or chest X-ray) + treatment records; latent TB must be treated for ≥ 4 weeks before biologic initiation
HBV serology (HBsAg, HBcAb, HBsAb; HBV DNA viral load if HBsAg+)
HCV, HIV, CBC, CMP, lipids at baseline
Exclusions: pregnancy, active infection, untreated TB, prosthetic joint with prior severe sepsis, malignancy or pre-malignancy, immunodeficiency

The purpose of these baseline labs is largely documentation, ruling out exclusions, and satisfying review process — not the "clinical benefit" the USPSTF framework measures. In Taiwan practice, IL-17 and IL-23 patients still receive the baseline panel (NHI requires it) even though the USPSTF grade is D, but follow-up testing can be substantially reduced. The article's value is reminding clinicians: grade D does not mean "never do it" — it means "no demonstrated benefit". Whether to test in any given patient still depends on personal risk, NHI requirements, and clinical judgment.

For the full NHI psoriasis biologic criteria (PASI ≥ 10, conventional therapy failure, week-12 evaluation, 2-year pause continuation, etc.), see our complete dermatology NHI regulations summary and biologics and targeted therapies overview.

Study limitations

USPSTF does not consider direct cost, but does evaluate downstream harms of false positives (anxiety, additional workup, unnecessary prophylactic treatment)
Most evidence comes from cohort studies and post-hoc safety pooled analyses of trials — there are no RCTs designed to directly compare "screen vs no-screen"
Some TNF-α HBV reactivation and LFT data come from pooled rheumatology/GI cohorts where MTX or other immunosuppressants amplified HBV reactivation risk — possibly overstating risk for psoriasis monotherapy
Trial eligibility criteria typically exclude HIV, CHF, pregnant, and recent-malignancy patients; real-world patient mix is broader, so extrapolation requires caution
Literature search ended November 2023, so the most recent data — including longer-term outcomes on newer agents like dual IL-17A/F inhibitors — may not be fully captured

Bottom line: what you can do

For psoriasis patients: at your next visit, ask your dermatologist "Which class am I on, and which routine labs are still needed under current evidence?" For IL-17 and IL-23 patients, many routine labs may reflect NHI policy rather than clinical benefit. But do not stop any scheduled monitoring on your own — stopping or reducing therapy must be discussed with the prescribing dermatologist.

For clinicians: USPSTF grades offer a framework to step outside historical convention. In Taiwan, baseline labs remain bound by NHI , but long-term monitoring can be tailored by class and risk. Maintain TB + HBV monitoring on TNF-α; focus on symptom inquiry (oral candidiasis, IBD) for IL-17; recognize that for low-risk IL-12/23 or IL-23 patients, routine asymptomatic bloodwork has very low evidence support. Individual risk factors — age, comorbidities, drug history, and Taiwan's high HBsAg carrier rate — remain the decisive axis.

Further reading:for psoriasis systemic treatment, see Psoriasis systemic treatment — complete patient guide; for biologic mechanism of action and drug selection, see Dermatology biologics and small-molecule targeted drugs — overview; for full Taiwan NHI coverage conditions, see Taiwan NHI rules for common dermatology drugs — complete reference。

References

Duong JQ, Razler DJ, Hrin ML, Huang WW, Feldman SR. To test or not to test? Revisiting the value of baseline screening and monitoring tests among biologic treatments for psoriasis using an evidence-based assessment. J Am Acad Dermatol. 2026;94(5):1438-1446. DOI: 10.1016/j.jaad.2025.09.123
Menter A, Strober BE, Kaplan DH, et al. Joint AAD-NPF guidelines of care for the management and treatment of psoriasis with biologics. J Am Acad Dermatol. 2019;80(4):1029-1072. PMID: 30772097
Snast I, Bercovici E, Solomon-Cohen E, et al. Active tuberculosis in patients with psoriasis receiving biologic therapy: a systematic review. Am J Clin Dermatol. 2019;20(4):483-491. PMID: 30859363
Snast I, Atzmony L, Braun M, Hodak E, Pavlovsky L. Risk for hepatitis B and C virus reactivation in patients with psoriasis on biologic therapies: a retrospective cohort study and systematic review. J Am Acad Dermatol. 2017;77(1):88-97.e5. PMID: 28291557
Chiu HY, Chiu YM, Chang Liao NF, et al. Predictors of hepatitis B and C virus reactivation in patients with psoriasis treated with biologic agents: a 9-year multicenter cohort study. J Am Acad Dermatol. 2021;85(2):337-344. PMID: 33484766
Torres T, Chiricozzi A, Puig L, et al. Treatment of psoriasis patients with latent tuberculosis using IL-17 and IL-23 inhibitors: a retrospective, multinational, multicentre study. Am J Clin Dermatol. 2024;25(2):333-342. PMID: 38217831
Gordon KB, Langley RG, Warren RB, et al. Bimekizumab safety in patients with moderate-to-severe plaque psoriasis: pooled data from up to 3 years of treatment in randomized phase III trials. Br J Dermatol. 2024;190(4):477-485. PMID: 38099445
Korzenik J, Larsen MD, Nielsen J, Kjeldsen J, Nørgård BM. Increased risk of developing Crohn's disease or ulcerative colitis in 17,018 patients while under treatment with anti-TNFα agents, particularly etanercept, for autoimmune diseases other than inflammatory bowel disease. Aliment Pharmacol Ther. 2019;50(3):289-294. PMID: 31157930
Wright S, Alloo A, Strunk A, Garg A. Real-world risk of new-onset inflammatory bowel disease among patients with psoriasis exposed to interleukin 17 inhibitors. J Am Acad Dermatol. 2020;83(2):382-387. PMID: 32119886
Davis MS, Spencer RK, Johnson CE, et al. Risk of cutaneous T cell lymphoma with psoriasis biologic therapies. Dermatol Ther (Heidelb). 2024;14(1):15-30.
Taiwan NHI Administration. National Health Insurance Drug Coverage Regulations (Biologics for Psoriasis section; revised effective 2025/6/1). Published 2025/4/23. https://www.nhi.gov.tw/
Taiwan FDA. Drug package inserts for each biologic (adalimumab, infliximab, etanercept, certolizumab, ustekinumab, secukinumab, ixekizumab, brodalumab, bimekizumab、guselkumab、risankizumab、tildrakizumab）. https://www.fda.gov.tw/

Do you really need annual blood tests on psoriasis biologics?