Vitiligo Relapse & Maintenance: TRM Biology and Practical Therapy Schemes

Key Takeaways

Relapse is driven by tissue-resident memory T cells (TRM) and the IFN-γ–CXCL9/10 chemokine loop that re-recruits cytotoxic T cells.
Maintenance should be site-specific: proactive topicals on face/neck; periodic NB-UVB taper or 308 nm excimer boosters for edges/acral zones.
Relapse risk is highest within the first 6–12 months after successful repigmentation and at Koebner-prone (friction/pressure) sites.
Structured photo follow-up and F-VASI/T-VASI tracking enable early intervention when borders reactivate.

TRM cells persist in previously affected skin, producing IFN-γ and maintaining a “primed” state.
Keratinocytes amplify via STAT1 → CXCL9/10, attracting CXCR3⁺ CD8 T cells and restarting cytotoxic injury.
Oxidative/mechanical stress (see oxidative stress article) can spark this loop.

Timeline: most relapses occur within 6–12 months after stopping light/topicals.
Sites: periorificial face does well but can relapse; acral sites (hands/feet) and high-friction areas are highest risk.
Signs: Wood’s lamp shows confetti-like micro-macules or border “sparkle” before clinical spread.

Table 1. Common maintenance strategies.

Strategy	Use case	Notes
Proactive tacrolimus 0.1% (face/neck)	Post-repigmentation	Thin layer 2–3 nights/week for 3–6 mo, then taper
NB-UVB taper	Generalized disease	Step-down from 2–3×/wk → 1×/wk → q2wk for 2–3 mo
Excimer 308 nm boosters	Edges/acral rims	2–4 sessions “mini-cycles” on reactivation
Topical JAK (label-eligible facial BSA)	Facial relapse risk	Intermittent maintenance per label with close monitoring
Trigger control	Koebner/friction	Barrier care, gear padding, emollients, sun safety

Table 2. Suggested pathways by site.

Site	Preferred maintenance	Rescue if reactivation
Face/neck	Proactive tacrolimus 0.1% 2–3×/wk	Add NB-UVB or label-eligible topical JAK
Trunk/limbs	NB-UVB taper + intermittent tacrolimus	NB-UVB step-up cycle; short excimer for borders
Acral (hands/feet)	Regular emollients + protective gear; NB-UVB taper	Excimer boosters + topicals

Standardize photography (see photo protocol) every 8–12 weeks in the first year.
Use F-VASI/T-VASI and Wood’s lamp to detect micro-relapse early.
Pre-book “rescue” slots (excimer/NB-UVB) for fast ramp-up when borders spark.

Table 3. Populate with regimen details per clinic.

Plan	Frequency	Duration	Stop rules
Tacrolimus proactive	2–3×/wk nights	3–6 mo	No border activity × 3 mo
NB-UVB taper	Weekly → q2wk	8–12 wks	Stable photos × 2 visits
Excimer boosters	2–4 sessions	Per cycle	Islands consolidate