Journal — European Society for Photodermatology (ESPD)

Illustrative example · not a congress contribution

Review

Wavelength-Specific Effects of Ultraviolet Radiation on Human Skin

Sample contribution — author list to be confirmed · April 2026

Abstract

Solar ultraviolet radiation reaches the Earth's surface across a continuous range of wavelengths, each interacting with human skin in distinct ways. This review summarises the main wavelength-specific effects of UVA, UVB and UVC on cutaneous tissue, from surface absorption to molecular damage and clinical consequences. Provided as an illustrative sample of an ESPD review article; figures are representative rather than empirical.

Introduction

Ultraviolet radiation is conventionally divided into three contiguous bands — UVA (315–400 nm), UVB (280–315 nm), and UVC (100–280 nm) — defined by wavelength and, consequently, by photobiological behaviour.

While UVC is almost entirely absorbed by stratospheric ozone and contributes little to terrestrial exposure under normal conditions, UVA and UVB together account for virtually all the ultraviolet reaching human skin and drive the spectrum of acute and chronic photodermatological outcomes.

The ultraviolet spectrum

The position of a wavelength along the electromagnetic spectrum determines its photon energy: shorter wavelengths carry higher energy and, in general, greater potential for direct molecular damage. Within the UV band, UVC is the most energetic and UVA the least.

Figure 1. UV bands alongside visible light.

Illustrative example · not a congress contribution

Penetration into the skin

Shorter UV wavelengths interact more strongly with surface layers and penetrate less deeply; longer wavelengths reach deeper structures of the dermis.

UVC, when present, is essentially absorbed within the stratum corneum and superficial epidermis. UVB acts predominantly within the epidermis, where it produces direct DNA photoproducts in keratinocytes. UVA, by contrast, penetrates to the dermis, where it exerts effects primarily through oxidative pathways.

Figure 2. Relative penetration depths of UVC, UVB and UVA.

Cellular and molecular effects

UVB induces the formation of cyclobutane pyrimidine dimers and 6-4 photoproducts in cellular DNA; these lesions, if unrepaired, contribute to mutagenesis and cutaneous carcinogenesis.

UVA acts largely indirectly, generating reactive oxygen species that damage lipids, proteins and DNA bases, and contributes substantially to photoageing and to immunomodulation in the skin.

Clinical implications

An understanding of wavelength-specific behaviour underpins much of clinical photodermatology: the choice of phototesting protocols, the design of phototherapeutic regimens, the formulation of sunscreens with appropriate UVA–UVB coverage, and the public-health messaging around photoprotection.

Conclusion

The cutaneous effects of ultraviolet radiation are not uniform but tightly coupled to wavelength. Continued investigation of these wavelength-specific mechanisms remains central to the work of photodermatology in clinic, laboratory and public health alike.

Illustrative example · not a congress contribution

Clinical study

Narrow-Band UVB Phototherapy in Moderate Plaque Psoriasis: An Illustrative Treatment-Response Profile

Sample contribution — author list to be confirmed · March 2026

Abstract

Narrow-band UVB phototherapy remains a first-line treatment for moderate plaque psoriasis. This illustrative summary presents a representative treatment-response profile across twelve weeks of standardised NB-UVB delivery and discusses implications for clinical scheduling and patient selection. Sample article and figure — provided for this prototype.

Background

NB-UVB exerts its therapeutic effect principally through induction of T-cell apoptosis and modulation of keratinocyte proliferation, restoring a more orderly pattern of epidermal turnover.

Representative results

A representative twelve-week treatment course produces a roughly monotonic reduction in mean PASI, with the greatest absolute change typically observed in the first six weeks of therapy.

Most patients reach a clinically meaningful endpoint (PASI 75) by the end of a standard course, with a smaller proportion progressing to PASI 90.

Figure. Mean PASI across twelve weeks of NB-UVB therapy.

Conclusion

NB-UVB remains a valuable, well-tolerated option in moderate plaque psoriasis. Realistic expectations about response timing — informed by representative trajectories such as the one shown here — help align patient and clinician on treatment goals.

Illustrative example · not a congress contribution

Survey

Self-Reported Sun-Protection Behaviour Across Selected European Populations

Sample contribution — author list to be confirmed · February 2026

Abstract

Sun-protection behaviour varies substantially across European populations, reflecting differences in climate, cultural attitudes and public-health messaging. This illustrative survey summary presents a representative cross-country comparison of self-reported use of SPF 30+ sunscreen. Sample article and figure — provided for this prototype.

Introduction

Effective photoprotection is one of the most actionable levers for reducing the long-term burden of skin cancer and photoageing, yet adherence to recommended practices remains uneven across European populations.

Findings

Self-reported regular use of SPF 30+ sunscreen during peak-UV months varies materially across the surveyed populations, with southern countries generally reporting higher use than northern ones.

The patterns are consistent with a combination of ambient UV exposure, cultural attitudes to sun and tan, and the historical strength of national public-health campaigns.

Figure. Self-reported SPF 30+ use across selected European populations.

Conclusion

Photoprotective behaviour is shaped by climate, culture and policy as much as by individual choice. Continued cross-country evaluation, paired with adaptive messaging, supports the society's broader mission of reducing the avoidable cutaneous consequences of solar UV.

Illustrative example · not a congress contribution

About this journal

This ESPD editorial collection connects member research and congress highlights. Calzavara-Pinton’s research summary precedes these three illustrative articles. The complete Vienna programme remains in the separate congress reader.

Authenticated ESPD members can send article requests directly to contributing authors through DermaHub.

No affiliation with a publisher’s journal or new peer review is claimed. Access to full articles remains subject to publication rights.

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Submission guidelines, article types and the editorial process will be linked here once confirmed with the society.

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Research, shared by our members.

Read. Reflect. Connect with the author.

Multiple actinic keratoses: a long-term approach

Illustrative examples

Wavelength-Specific Effects of Ultraviolet Radiation on Human Skin

Narrow-Band UVB Phototherapy in Moderate Plaque Psoriasis: An Illustrative Treatment-Response Profile

Self-Reported Sun-Protection Behaviour Across Selected European Populations

Topics for future contributions.

For members

For authors

ESPD Journal

Contents

Multiple actinic keratoses: a long-term approach

Wavelength-Specific Effects of Ultraviolet Radiation on Human Skin

Introduction

The ultraviolet spectrum

Penetration into the skin

Cellular and molecular effects

Clinical implications

Conclusion

Narrow-Band UVB Phototherapy in Moderate Plaque Psoriasis: An Illustrative Treatment-Response Profile

Background

Representative results

Conclusion

Self-Reported Sun-Protection Behaviour Across Selected European Populations

Introduction

Findings

Conclusion

About this journal

Editorial colophon

For authors

Stay connected