Excimer 308 nm in Vitiligo: Focal Therapy for Face/Neck and Acral Margins

Key Takeaways

Targeted 308 nm is effective for limited facial/neck lesions and expanding edges of patches.
Acral sites (hands/feet) respond slower; pairing with tacrolimus/pimecrolimus improves odds.
Typical schedule: 2–3×/week, 20–30 sessions initial; visible perifollicular islands by weeks 4–8.
Adverse events are mostly grade 1–2 erythema; careful dose titration minimizes burns.

Abstract

Excimer 308 nm provides high-fluence, small-field UVB for focal vitiligo. Evidence from RCTs and cohorts supports superiority over placebo/observation for facial lesions and utility as an adjunct for acral margins. We summarize practical dosing, targeting strategies, site-specific outcomes, combinations with calcineurin inhibitors, and safety.

Protocols & Dosing

Table 1. Typical 308 nm dosing frameworks.

Parameter	Typical setting	Notes
Frequency	2–3 sessions/week	≥48 h between sessions
Start dose	150–300 mJ/cm²	Phototype & site adjusted
Increment	10–25% per treatment	Hold if erythema >24 h
Course length	20–30 sessions (initial)	Extend if improving to 40–50
Field size	2–5 cm spot/handpiece	Feather at borders to blend

Clinical Indications & Targeting

Focal/segmental lesions on face/neck or cosmetically sensitive zones.
Advancing edges of nonsegmental patches; perilesional halos.
Acral margins where cabinet NB-UVB underperforms.

Efficacy by Anatomic Site

Table 2. Response patterns (typical).

Site	Response	Notes
Face/neck	High	Early islands, rapid F-VASI gains
Trunk	Moderate	Better at edges than center
Acral	Low–moderate	Improves with tacrolimus/pimecrolimus

Combination with Topicals

Tacrolimus 0.1% / Pimecrolimus 1% applied between sessions increases response on face/neck and acral margins.
Sequence: treat with excimer → apply topical later the same day to reduce irritation.
Use with NB-UVB cabinet for widespread disease; excimer for resistant foci.

Safety

Table 3. Common adverse events.

Event	Pattern	Management
Erythema/tenderness	Mild, dose-related	Hold/reduce dose; emollients
Blistering (rare)	Over-titration	Immediate rest; lower restart
Hyperpigmentation	Transient	Feather borders; adjust spacing

Outcome Tables (framework)

Table 4. Study outcomes (fill with numerics).

Outcome	Excimer	Comparator	Interpretation
F-VASI % change (face, 12–24 wks)	—	Vehicle/observation	Favours excimer
Responder rate (F-VASI50/75)	—	—	Higher on face/neck
Acral response	—	—	Improves with calcineurin inhibitor

Limitations

Small RCTs and heterogeneous protocols; durability data limited; access and operator technique influence outcomes.

References

Randomized and cohort studies of 308 nm excimer in facial and acral vitiligo.
Combination studies with tacrolimus/pimecrolimus and cabinet NB-UVB.
Guidelines on targeted phototherapy dosing and safety.