Merete Haedersdal

University of Copenhagen Bispebjerg Hospital Denmark · Dept of Dermatology

Objectives: The impact of skin hydration on patterns of thermal injury produced by ablative fractional lasers (AFLs) is insufficiently examined under standardized conditions. Using skin with three different hydration levels, this study assessed the effect of hydration status on microchannel dimensions generated by a fractional CO2 laser. Methods:...

Fractional picosecond-domain lasers (PSL) induce optical breakdown, which correlates histologically to vacuolization in the epidermis and dermis. In this ex vivo porcine study, we sought to establish a framework for the investigation of laser-tissue interactions and their dependence on melanin density. Light- (melanin index: 24.5 [0–100]), medium-...

Background: Photodynamic therapy (PDT) is approved for treatment of actinic keratoses (AKs) and field-cancerisation. Pretreatment with pharmacological compounds holds potential to improve PDT efficacy, through direct interaction with PpIX formation or through an independent response, both of which may improve PDT treatment. Objective: To present...

Ultraviolet radiation is the primary risk factor for keratinocyte carcinoma. Because of increasing incidence rates, new methods of photoprotection must be explored. Oral supplementation with photoprotective compounds presents a promising alternative. Phytochemical compounds like hesperidin methyl chalcone, phloroglucinol, and syringic acid are part...

Methyl aminolevulinate (MAL) is a topical compound approved for use with photodynamic therapy (PDT) for the treatment of actinic keratosis (AK) and field cancerization in certain countries. There exists a high burden of disease for patients with AK: repeated treatments are required, there is a known risk of progression to keratinocyte carcinoma, an...

Actinic keratoses are pre-malignant skin lesions that require personalized care, a lack of which may result in poor treatment adherence and suboptimal outcomes. Current guidance on personalizing care is limited, notably in terms of tailoring treatment to individual patient priorities and goals and supporting shared decision-making between healthcar...

Background: Ablative fractional CO2 laser (AFL) is an established first-line energy-based treatment for acne scars. Microneedle radiofrequency (MNRF) is an emerging treatment, also targeting the skin in fractions. No studies have so far compared AFL with MNRF for acne scars in a direct controlled, side-by-side comparison. In this study, we compare...

Background and objectives: Home-use intense pulsed light (IPL) hair removal devices are convenient for consumers. Consumer safety associated with home-use IPL devices, however, remains a subject of interest. In this descriptive analysis, we assessed the most commonly reported adverse events (AEs) for a home-use IPL device from postmarketing survei...

Anal cancer risk is increased in certain risk groups including people living with HIV (PLWH), especially in men who have sex with men, but also in organ transplant recipients and women with a history of cervical or vulva dysplasia or cancer. High-resolution anoscopy (HRA) is a tool to diagnose anal high-grade squamous intraepithelial lesions (HSIL)...

Background and objectives: Solid organ transplant recipients (SOTRs) are at increased risk of skin cancer and suffer from greater disease-specific morbidity and mortality. To risk stratify the expanding SOTR population for more targeted skin cancer screening, a detailed understanding of risk factors is needed. Using combined clinical and pathologic...

Background: Kidney transplant recipients (KTRs) have increased risk of human papillomavirus (HPV)-related cancers, including cervical and anal cancer. In this cross-sectional clinical study, we investigated the prevalence of cervical high-risk HPV (hrHPV) and low-risk (lrHPV), risk factors for cervical hrHPV infection, and the prevalence of cervic...

The aim of Quantitative mass spectrometry imaging (Q-MSI) is to provide distribution analysis and quantitation from one single mass-spectrometry-based experiment, and several quantitation methods have been devised for Q-MSI. Mimetic tissue models based on spiked tissue homogenates are considered one of the most accurate ways to perform Q-MSI, since...

The use of immune checkpoint inhibitors (ICI) is expanding with the approval for advanced/metastatic keratinocyte carcinoma; however, most tumors are non-aggressive. Local administration could broaden ICI, but adequate immune response might require an immune-attractive adjuvant such as ablative fractional laser (AFL). Accordingly, this study aimed...

Background: There is a lack of efficacious topical treatments for patients suffering from psoriatic nail disease (PND). Objectives: We investigated the efficacy of Calcipotriol-Betamethasone Dipropionate (Cal/BD) foam with and without ablative fractional laser (AFL) in patients with PND. Methods: A total of 144 nails from eleven patients were...

Systemic treatment with hedgehog inhibitors (HHis) is available to treat basal cell carcinomas but their utility is limited by adverse effects. Topical delivery methods may reduce adverse effects, but successful topical treatment depends on sufficient skin uptake, biological response, and time in tumor tissue. The aim of this review was to evaluate...

Objective: Microwave thermolysis (MWT) is an emerging treatment for axillary hyperhidrosis reducing both sweat and odor. No prior studies have investigated and compared the different available energy settings of the MWT device. This study evaluated patient-reported outcome measures (PROMs) for axillary hyperhidrosis and osmidrosis following MWT tr...

Objectives Ablative fractional laser (AFL) is a well-established modality for treating ultraviolet radiation (UVR)-induced skin photodamage. We aimed to investigate the potential of AFL to delay squamous cell carcinoma (SCC) formation and prevent photodamage in a preclinical UVR-induced SCC model. Materials and Methods Hairless C3.Cg-Hrhr/TifBomTa...

Introduction Actinic keratosis (AK) is the most common precancerous skin condition caused by long-term UV exposure. Given the high recurrence rate of 15%–53%, identifying safe and effective treatment options is warranted. AVX001, a cytosolic phospholipase A 2 α (cPLA 2 α) enzyme inhibitor, is a novel anti-inflammatory drug for field-directed, self-...

Background/aim: The effect of vitamin D on skin carcinogenesis is unclear. Vitamin D derivatives may protect against ultraviolet radiation (UVR)-induced DNA damage, immune suppression, and skin carcinogenesis. However, some epidemiological studies have reported an increased incidence of skin cancer associated with high serum vitamin D levels. We i...

Importance Laser-assisted drug delivery (LADD) is used for various medical and cosmetic applications. However, there is insufficient evidence-based guidance to assist clinicians performing LADD. Objective To develop recommendations for the safe and effective use of LADD. Evidence Review A systematic literature review of Cochrane Central Register...

Background Increasing costs and complexity in clinical trials requires recruitment of more narrowly defined patient populations. However, recruitment for clinical trials remains a considerable challenge. Aim Our overall aim was to quantify recruitment performance in industry-sponsored phase III clinical trials conducted globally during 2008–2019 w...

The skin barrier generally limits the topical delivery of hydrophilic molecules. Ablative fractional laser (AFL) facilitates cutaneous drug uptake of smaller hydrophilic compounds in several studies. In this imaging-based study, we aim to investigate the cutaneous biodistribution of two different-sized hydrophilic compounds delivered by an ablative...

Background: There is limited evidence on the best available treatment options for capillary malformations (CMs), mainly due to the absence of uniform outcome measures in trials on therapies. A Core Outcome Set (COS) enables standard reporting of trial outcomes, which facilitates comparison of treatment results. Objectives: To develop a core outc...

Background There is variation in the outcomes reported in clinical studies of basal cell carcinoma (BCC). This can prevent effective meta-analyses to answer important clinical questions. Objective To identify a recommended minimum set of core outcomes for BCC clinical trials. Methods Patient and professional Delphi process to cull a long-list, cu...

Introduction: The ability of ablative fractional lasers (AFL) to enhance topical drug uptake is well established. After AFL delivery, however, drug clearance by local vasculature is poorly understood. Modifications in vascular clearance may enhance AFL-assisted drug concentrations and prolong drug dwell time in the skin. Aiming to assess the role...

Background Kidney transplant recipients (KTRs) have increased risk of human papillomavirus (HPV)-related anogenital (pre-)cancers, including anal high-grade intraepithelial lesions (HSIL) and cancer. Previous studies on anal high-risk HPV among KTRs are sparse. Methods In a cross-sectional study, we included 247 KTRs and 248 controls from a dermat...

Background: Ex-vivo confocal microscopy (EVCM) enables examination of tissue alterations immediately after treatment with energy-based devices (EBDs). This proof-of-concept study aimed to describe EBD-induced tissue effects in ex-vivo porcine skin after treatment with microneedle radiofrequency (MNRF) and ablative fractional CO2 -laser (AFL) using...

Purpose: Conventional oral antifungal therapies for onychomycosis (OM) often do not achieve complete cure and may be associated with adverse effects, medical interactions, and compliance issues restricting their use in a large group of patients. The topical treatment provides an alternative to bypass the systemic side effects but is limited by the...

Background: Increasing costs and complexity in clinical trials requires recruitment of more narrowly defined patient populations. However, recruitment for clinical trials remains a considerable challenge. Aim: Our overall aim was to quantify recruitment performance in industry-sponsored phase III clinical trials conducted globally during 2008-2019...

Background: The growing interest in the visualization of psoriatic nail unit changes has led to the discovery of an abundance of image characteristics across various modalities. Objective: To identify techniques for non-invasive imaging of nail unit structures in psoriatic patients and review extracted image features to unify the diverse termino...

Background: Patients with hypertrophic scars (HTS) risk reduced quality of life due to itching, pain, poor cosmesis, and restriction of movement. Despite good clinical efficacy, patients are often reluctant to undergo repeated needle injections due to pain or needle phobia. Objectives: To evaluate the applicability of needle-free pneumatic jet i...

Background: Despite the widespread use of optical coherence tomography (OCT) for imaging of keratinocyte carcinoma, we lack an expert consensus on the characteristic OCT features of basal cell carcinoma (BCC), an internationally vetted set of OCT terms to describe various BCC subtypes, and an educational needs assessment. Objectives: To identify...

Background: Intralesional bleomycin (BLM) administration by needle injection is effective for keloids and common warts but has significant drawbacks, including treatment-related pain and highly operator-depended success rates. Electronic pneumatic injection (EPI) is a promising, less painful, needle-free delivery method that potentially enables mo...

Objectives: Needle-free jet injectors have been used in dermatological practice for many years. However, predefined clinical endpoints that guide physicians to choose optimal device settings have not been clearly defined. Here, we evaluate immediate skin responses as clinical endpoints for needle-free jet injector treatments. Methods: We injecte...

Objectives Needle-free jet injectors are frequently used in dermatological practice. Injection-generated small-droplet aerosols could be harmful upon inhalation when chemotherapeutics, like bleomycin, are used. Here, we aim to explore jet injector-induced small-droplet aerosol formation of bleomycin in relation to air ventilation and to provide saf...

Background and Objectives Current cancer immunotherapeutic treatment with PD-1 inhibitors is administered systemically. However, a local treatment strategy may be advantageous as it could provide targeted drug delivery as well as attenuate side effects seen with systemic treatments. For keratinocyte cancers, where surgical excision is not always ap...

Bleomycin (BLM) is being repositioned in dermato-oncology for intralesional and intra-tumoural use. Although conventionally administered by local needle injections (NIs), ablative fractional lasers (AFLs) can facilitate topical BLM delivery. Adding local electroporation (EP) can augment intracellular uptake in the target tissue. Here, we characteri...

Background and Objectives There is a growing need for effective topical treatments for basal cell carcinoma (BCC). By altering the skin barrier, ablative fractional lasers (AFLs) enhance cutaneous uptake of the synergistic chemotherapeutic agents, cisplatin, and 5-fluorouracil (5-FU). In our recently reported clinical trial, AFL-assisted delivery o...

Fast diagnosis of suspicious pigmented skin lesions is imperative, but current bedside skin imaging technologies are either limited in penetration depth or resolution. Combining imaging methods is therefore highly relevant for skin cancer diagnostics. This pilot study evaluates the ability of optical coherence tomography, reflectance confocal micro...

To enhance the efficacy of photodynamic therapy (PDT) for actinic keratosis (AKs), physical and chemical pre-treatments, such as calcipotriol (CAL) have been suggested. To compare the long-term 12-month efficacy and safety between methylaminolevulinate (MAL)-PDT and prior application of topical CAL versus conventional MAL-PDT for AKs of the scalp....

Background and objectives: Acne scars are one of the most distressing and long-term consequences of acne vulgaris, with damaging effect on a person's physical, mental, and social well-being. Numerous treatment options are available including surgical and nonsurgical techniques, depending on the clinical presentation. Although considerable advances...

The role of the immune system in cancer growth is well recognized and the development of immunotherapy represents a breakthrough in cancer treatment. Recently, the use of systemic immunotherapy was extended to keratinocyte carcinoma (KC), specifically locally advanced and metastasizing basal and squamous cell carcinoma. However, since most KC lesio...

Objectives Nailfold video capillaroscopy (NVC) and angiographic optical coherence tomography (OCTA) have potential in diagnosing psoriatic arthritis (PsA) and differentiating it from psoriasis vulgaris (PsO) and hand osteoarthritis (OA). We aimed to assess the diagnostic properties of NVC and OCTA in patients with PsA compared with patients with Ps...

Background: The suspected link between human papillomavirus (HPV) and the development of premalignant and malignant skin lesions remains inadequately examined in clinical settings. This case series describes HPV vaccination as an off-label adjuvant therapy for actinic keratosis (AK). Methods: Twelve immunocompetent AK patients underwent HPV vacc...

Background and objectives: Image-guided quantitative and semi-quantitative assessment of skin can potentially evaluate treatment efficacy. Optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) are ideal for this purpose. This study assessed clinically relevant statistical changes in RCM and OCT features in photoaged skin aft...

Ultraviolet radiation (UVR) arising from sun exposure represents a major risk factor in the development of keratinocyte carcinomas (KCs). UVR exposure induces dysregulated signal transduction, oxidative stress, inflammation, immunosuppression and DNA damage, all of which promote the induction and development of photocarcinogenesis. Because the inci...

Basal cell carcinoma (BCC) is the most common type of cancer and an increasing incidence stimulates the interest in new treatments such as electrochemotherapy (ECT) with bleomycin. This systematic review focuses on literature from the MEDLINE, Embase, Web of Science, and Cochrane databases. Bleomycin-ECT studies (n = 32) were sorted by level of evi...

Bedside diagnosis of skin cancer remains a challenging task. The real-time non-invasive technology of optical coherence tomography (OCT) masters a high diagnostic accuracy in basal cell carcinoma (BCC) but a lower specificity in recognizing imitators and other carcinomas. We investigate the delicate signal of papillary dermis using an in-house deve...

Background: Due to a large variety in treatment outcomes reported in therapeutic trials and lacking patient-relevant outcomes, it is hard to adequately compare and improve current therapies for patients with capillary malformations (CMs). The Core Outcome Set for Capillary Malformations (COSCAM) project aims to develop a core outcome set (COS) for...

Background and Objectives Keratinocyte carcinoma (KC) is the most common cancer worldwide, and squamous cell carcinoma (SCC) is the second most frequent subtype. Ablative fractional laser (AFL)‐assisted drug delivery significantly enhances the uptake of topically applied drugs. The objective of this study was to assess tumor response and perform a...

Background Adapalene‐benzoyl peroxide (A‐BPO) is a first‐line topical treatment for acne vulgaris. In vivo reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) detect micromorphological changes over time and visualize transfollicular delivery. Objectives To visualize temporal, subclinical effects of A‐BPO on acne micromorph...

Background and Objective We evaluated a new handheld stereoscopic imaging system capable of visualizing scars with digital three‐dimensional (3D) models and providing automated morphometric estimates. The objective was to validate the repeatability and accuracy of intra‐ and inter‐investigator scan results. Study Design/Materials and Methods Engin...

We investigated the utility of the fluorescent dye (Deep Red Anthraquinone 5) DRAQ5 for digital staining of optically sectioned skin in comparison to Acridine Orange (AO). Eight fresh‐frozen thawed Mohs discard tissue specimens were stained with AO and DRAQ5, and imaged using an ex vivo confocal microscope at three wavelengths (488 nm and 638 nm fo...

Background and Objectives Porcine skin is a widely used model in diffusion studies, but its usefulness for laser‐assisted drug delivery (LADD) has not been evaluated in comparison with human skin. This study compared porcine and human skin in ex vivo LADD diffusion studies. Study Design/Materials and Methods Ex vivo ablative fractional laser (AFL)...

Background and objectives: Thermo-mechanical fractional injury (TMFI) impacts the skin barrier and may increase cutaneous drug uptake. This study investigated the potential of TMFI in combination with 5-aminolevulinic acid (ALA) cream and gel formulations to enhance Protoporphyrin IX (PpIX) fluorescence at the skin surface and in the skin. Study...

Background and Objectives: Rising incidences of basal cell carcinoma (BCC) have increased the need for effective topical therapies. By enhancing cutaneous uptake of the chemotherapeutic agents, cisplatin and 5‐fluorouracil (5‐FU), laser‐assisted delivery may provide a new combi- nation treatment for BCC. Accordingly, this study aimed to evaluate tu...

Background and objectives: PD-L1 is a tumor ligand that binds to the PD-1 receptor on immune cells, thereby inhibiting the antitumor immune response. The antibody nivolumab is a PD-1 inhibitor, Food and Drug Administration approved for systemic treatment of several aggressive cancer types. Topically applied nivolumab may hold potential as a future...

Background and Objectives While optical imaging is a useful technique to quantitate morphological differences and treatment effects, comparative investigations of the various techniques are lacking. This study aimed at evaluating intermethod agreement, reliability, and technical limitations of wide‐field microscopy (WFM), reflectance confocal micro...

OBJECTIVES: The impact of optical tissue clearing on optical coherence tomography (OCT) for nail tissue imaging has not been investigated. This study seeks to compare the effects of an emollient and water on visualization of micromorphology and morphometric outcomes. MATERIALS AND METHODS: Thirty-six healthy nail plates were processed with a fract...

Early laser treatment during wound healing has increasingly gained focus to improve scar formation1. The majority of trials addressing early laser intervention for improving scar formation present short follow‐up time of 1‐3 months2. Considering the pathophysiology of scar formation, a scar is not mature until a year post‐injury. Thus, the effect o...

Background: Renal transplant recipients (RTRs) have increased risk of human papillomavirus (HPV)-related cancers, including anal cancer. We investigated the prevalence of anal high-grade intraepithelial lesions (HSIL) in RTRs compared with immunocompetent controls and risk factors for anal HSIL in RTRs. Methods: We included 247 RTRs and 248 cont...

Background and Objectives Mycological diagnosis of onychomycosis is based on direct microscopy using external fluorophores to visualize fungal tissue in nail samples and agar culture. Ultraviolet fluorescence excitation imaging (u‐FEI) has shown potential in monitoring biological processes by exploiting variations in autofluorescence. This study ai...

Background and Objectives Electronic pneumatic injection (EPI) is a technique for dermal drug delivery, which is increasingly being used in clinical practice. However, only few studies have been reported on cutaneous drug distribution and related clinical endpoints. We aimed to visualize the immediate cutaneous drug distribution, changes in skin ar...

Introduction While laser technology has expanded the armamentarium of treatment for various skin diseases during the past years, heterogeneity in study outcomes hampers comparability and appropriate evidence synthesis. Part of these issues can be addressed by developing a generic outcome set. Using the Delphi method, this study aims to seek consens...

Oral administration of vismodegib for basal cell carcinoma treatment is limited by significant class-specific systemic side-effects. We investigated the approach of combining ablative fractional laser (AFL)-assisted drug delivery with an extended-release microemulsion formulation of vismodegib to provide efficient cutaneous delivery in vivo. The de...

Background: Photodynamic therapy with Protoporphyrin IX (PpIX) is well-established for keratinocyte dysplasia. PpIX fluorescence can be quantified at the skin surface and within skin layers, but their relation is previously undescribed. The study objective was to assess the relation between skin surface PpIX fluorescence and PpIX fluorescence in e...

Keratinocyte carcinomas (KC) are the most common malignant human neoplasms. Although surgery and destructive approaches are first-line treatments, topical therapies are commonly used. Due to limited uptake of topical agents across the skin barrier, clearance rates are often sub-optimal. In pre-clinical investigations, ablative fractional laser (AFL...

Background: Knowledge of what the pharmaceutical industry emphasizes when assessing trial sites during site selection is sparse. A better understanding of this issue can improve the collaboration on clinical trials and increase knowledge of how to attract and retain industry-sponsored trials. Accordingly, we investigated which site-related qualiti...

In addition to approved indications in non-melanoma skin cancer in immunocompetent patients, topical photodynamic therapy (PDT) has also been studied for its place in the treatment of, as well as its potential to prevent, superficial skin cancers in immune-suppressed patients, although sustained clearance rates are lower than for immune-competent i...