Recalcitrant hand and foot warts successfully treated with photodynamic therapy with topical 5-aminolaevulinic acid: a pilot study

The use of photodynamic therapy in medical practice

Cancer therapy, especially for tumors near sensitive areas, demands precise treatment. This review explores photodynamic therapy (PDT), a method leveraging photosensitizers (PS), specific wavelength light, and oxygen to target cancer effectively. Recent advancements affirm PDT's efficacy, utilizing ROS generation to induce cancer cell death. With a history spanning over decades, PDT's dynamic evolution has expanded its application across dermatology, oncology, and dentistry. This review aims to dissect PDT's principles, from its inception to contemporary medical applications, highlighting its role in modern cancer treatment strategies.

Effect of 5-Aminolevulinic Acid Photodynamic Therapy on Aspergillus fumigatus Biofilms in Vitro

Aspergillus fumigatus biofilm development results in enhanced pathogenicity and treatment resistance. Most contemporary antibiotics, however, are unable to eliminate biofilms. In recent years, with the application of new photosensitizers and the development of treatment, ALA-PDT (5-aminolevulinic acid photodynamic treatment) has achieved remarkable curative effect in the treatment of fungal infectious diseases; however, no research has been conducted on ALA-PDT against A. fumigatus. This study investigated the inhibitory effect of ALA-PDT at various 5-aminolevulinic acid concentrations and light doses on A. fumigatus planktonic and biofilms in vitro. We found that ALA-PDT may successfully inhibit the development of A. fumigatus biofilm and disintegrate mature biofilm. After ALA-PDT treatment, the adherence rate and vitality dramatically decreased, and the biofilm's structure was severely compromised. Our findings show for the first time that ALA-PDT may be used to prevent the formation of A. fumigatus biofilm and disturb the structure of mature biofilm, and that it could be employed as a therapeutic therapy for A. fumigatus superficial infection.

The application of physical pretreatment in photodynamic therapy for skin diseases

Photodynamic therapy (PDT) is widely used in skin diseases; the response rate of PDT treatment varies widely. The limited penetration in the tissue of photosensitizers influenced the penetration depth of PDT, which obviously impacts the therapeutic effect. The studies have improved the efficacy of PDT through various pretreatment applications; especially, the physical pretreatment had achieved significant outcomes. We will review the physical pretreatment to optimize the efficacy of PDT in skin diseases by searching the literature on this topic. The types of physical pretreatment commonly used in the clinical practice are discussed: curettage, superficial shaving, laser, surgical resection, plum-blossom needles, and microneedles. Compared with PDT alone, the physical pretreatment before PDT application was generally improved the efficacy and reduced the recurrence, especially in actinic keratoses (AK), Bowen disease (BD), basal cell carcinoma (BCC), and viral warts. The application of the physical pretreatments before PDT may improve the efficacy of PDT in various skin diseases. However, each kind of physical pretreatment has the benefit and shortcoming, and the applicable situation is different.

The application of medical scale in the treatment of plantar warts: analysis and prospect

Plantar warts are common cutaneous diseases on the sole caused by the human papillomavirus, with a high annual incidence rate of 14%. It often causes pain, which impairs quality of life of patients. Numerous therapeutic options for plantar warts exist with variable success. However, all of them, including first-line treatment, have different adverse reactions or high recurrence rates. There is no one effective method for all patients. The choice of treatment method puzzles doctors. With the help of medical scales, we can analyze the patients' condition, so as to guide the choice of treatment methods, which is of great significance for the individualized treatment of patients with plantar warts. This review takes cryotherapy, intralesional injection of bleomycin and photodynamic therapy as examples to discuss the application of medical scales in the treatment of plantar warts, summarizes the scales that can be used to evaluate the status of plantar wart, adverse reactions, prognosis and patient's financial situation, and discusses their clinical and scientific value. We hope to use scales to consider the severity of plantar warts and economic level, help different patients to choose different treatment options, and make suggestions on the evaluation of the adverse reactions and treatment effect.

A Critical Reappraisal of Off-Label Use of Photodynamic Therapy for the Treatment of Non-Neoplastic Skin Conditions

BACKGROUND

In the past 30 years, topical photodynamic therapy (PDT) has been investigated for the treatment of a broad spectrum of cosmetic, inflammatory, and infectious skin conditions with variable, and often contrasting, results. However, the non-expert clinician may be in difficulty evaluating these results because different sensitizers, concentrations, formulations, light sources, and irradiation protocols have been used. In addition, many of these studies have poor quality design being case reports and uncontrolled studies of few cases.

SUMMARY

With the aim to clarify the potential usefulness of PDT for the treatment of infectious and inflammatory skin diseases as well as selected cosmetic indications, we searched for randomized controlled clinical trials, non-randomized comparative studies, retrospective studies, and case series studies with a number of at least 10 patients, published since 1990. Later, we reappraised the results in order to give a simple critical overview. Key Messages: Evidence from the literature seems to strongly support the use of ALA- and MAL-PDT for the treatment of common skin diseases such as acne, warts, condylomata, and Leishmania skin infection and for photorejuvenation, i.e., the correction of selected cosmetic changes of aging and photoaging. For other disorders, the level of evidence and strength of recommendation are lower, and controlled randomized studies with prolonged follow-ups are necessary in order to assess the clinical usefulness and other potential advantages over current treatment options.

European Dermatology Forum guidelines on topical photodynamic therapy 2019 Part 2: emerging indications - field cancerization, photorejuvenation and inflammatory/infective dermatoses

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 individuals. PDT using a nanoemulsion of ALA in a daylight or conventional PDT protocol has been approved for use in field cancerization, although evidence of the potential of the treatment to prevent new SCC remained limited. High-quality evidence supports a strong recommendation for the use of topical PDT in photorejuvenation as well as for acne, refractory warts, cutaneous leishmaniasis and in onychomycosis, although these indications currently lack approvals for use and protocols remain to be optimized, with more comparative evidence with established therapies required to establish its place in practice. Adverse events across all indications for PDT can be minimized through the use of modified and low-irradiance regimens, with a low risk of contact allergy to photosensitizer prodrugs, and no other significant documented longer-term risks with no current evidence of cumulative toxicity or photocarcinogenic risk. The literature on the pharmacoeconomics for using PDT is also reviewed, although accurate comparisons are difficult to establish in different healthcare settings, comparing hospital/office-based therapies of PDT and surgery with topical ointments, requiring inclusion of number of visits, real-world efficacy as well as considering the value to be placed on cosmetic outcome and patient preference. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical photodynamic therapy in Dermatology prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

Efficacy of the combination of superficial shaving with photodynamic therapy for recalcitrant periungual warts

BACKGROUND

Periungual warts are a viral infectious disease that occurs in a particular location. It is difficult to eliminate completely, and recurrence is common. Photodynamic therapy (PDT) as an option that has been widely recommended to treat viral warts. However, there are always a few patients with poor efficacy after PDT treatment. We have considered that the reason is the limitation of PDT penetrating deep into tissue. Thus, we combined superficial shaving with PDT to treat recalcitrant periungual warts.

METHODS

Twenty-three patients had a total of 61 periungual wart lesions. All patients had recalcitrant periungual warts that had failed to respond to various treatments that had poor curative effects. After local injection of anesthesia, the lesions were shaved in situ, and PDT was performed immediately. A total of three sessions of PDT were applied for each patient after only one superficial shaving. The overall clinical response rate, recurrence rates, cosmetic outcomes, adverse events, patient satisfaction and quality of life were assessed. The potential risk factors have also been recorded.

RESULTS

We achieved a 96% success rate (defined as more than 50% on clearance) in our 23 patients using combination superficial shaving with PDT after treatment for 3 months. At the 12-month follow-up, 21 patients (91%) had excellent cosmetic outcomes. All patients had satisfactory therapeutic effects and significant improvement in the quality of life. Pain during the illumination process was the main adverse event, but all patients were able to tolerate it. We also found that frequent or continuous hand activity, such as playing Mah-jong, may be a potential risk factor for periungual warts.

CONCLUSION

Our results offer promise for combining superficial shaving with PDT as an effective and safe therapy for patients with periungual warts, especially for those periungual warts that are recurrent, have multiple lesions, and thickness corneum stratum of lesions. For nails that are not suitable for routine surgery, combined superficial shaving with PDT is recommended.

The background and philosophy behind daylight photodynamic therapy

Conventional photodynamic therapy (PDT) is associated with side effects, primarily related to the waiting time between pretreatment with application of photosensitizer and illumination. Pain during illumination is a major issue for the patients and options for effective pain relief are limited. Post-treatment inflammation can often be severe and cause inconvenient down-time for the patients and their employers. To avoid the problems of pain and patients crowding in the clinic we eliminated red light treatment of high PpIX concentration and introduced illumination in daylight which may be performed at home. We also investigated if protoporphyrin IX (PpIX) could be activated continuously during its formation which might reduce pain and inflammation. Continuous activation of PpIX during its formation turned out to minimize pain as single PpIX molecules are activated continuously without accumulation of PpIX in the skin. PpIX molecules are formed in the mitochondria and the photodynamic effect only takes place in the mitochondria when continuously activated. This results primarily in apoptosis with little inflammation. Continuous activation of PpIX can be obtained by performing photodynamic therapy in daylight, as well as with daylight-emitting light sources of appropriate wavelengths. Use of daylight prevents the patients from crowding in the clinic. Daylight-PDT completely fulfils the purpose of minimizing pain and inflammation, as well as limiting the strain on the clinic treating the patients.

Off-label photodynamic therapy for recalcitrant facial flat warts using topical 5-aminolevulinic acid

The facial flat wart (verruca plana) is one of the most common reasons for dermatology and primary care visits. Although there are many therapeutic modalities, no single therapy has been proven to be completely curative. Case reports and uncontrolled studies suggested that photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) can effectively treat recalcitrant facial flat warts. A total of 12 patients with recalcitrant facial flat warts were enrolled in the study. ALA gel (10 %) was applied topically to lesions and incubated for 3 h. The lesions were irradiated by an LED light of 630 ± 10 nm at dose levels of 60-100 mW/cm. Clinical assessment was conducted before and after every treatment for up to 24 weeks. Among the ten patients completing three sessions of ALA-PDT, five had complete lesions clearance, and the other five patients were significantly improved. At the 24-week follow-up, the average effective rate was 88.8 %, with no recurrences. No significant side effects were reported. A low-dose topical ALA-PDT regimen using 10 % ALA, 3 h incubation, and a red light source for three treatment sessions are suggested as the optimal scheme for the treatment of recalcitrant flat warts on the face in Chinese patients. Superior efficacy is found in elevated or active period lesions with mild side effects.

Topical PDT in the Treatment of Benign Skin Diseases: Principles and New Applications

Photodynamic therapy (PDT) uses a photosensitizer, light energy, and molecular oxygen to cause cell damage. Cells exposed to the photosensitizer are susceptible to destruction upon light absorption because excitation of the photosensitizing agents leads to the production of reactive oxygen species and, subsequently, direct cytotoxicity. Using the intrinsic cellular heme biosynthetic pathway, topical PDT selectively targets abnormal cells, while preserving normal surrounding tissues. This selective cytotoxic effect is the basis for the use of PDT in antitumor treatment. Clinically, PDT is a widely used therapeutic regimen for oncologic skin conditions such as actinic keratosis, squamous cell carcinoma in situ, and basal cell carcinoma. PDT has been shown, under certain circumstances, to stimulate the immune system and produce antibacterial, and/or regenerative effects while protecting cell viability. Thus, it may be useful for treating benign skin conditions. An increasing number of studies support the idea that PDT may be effective for treating acne vulgaris and several other inflammatory/infective skin diseases, including psoriasis, rosacea, viral warts, and aging-related changes. This review provides an overview of the clinical investigations of PDT and discusses each of the essential aspects of the sequence: its mechanism of action, common photosensitizers, light sources, and clinical applications in dermatology. Of the numerous clinical trials of PDT in dermatology, this review focuses on those studies that have reported remarkable therapeutic benefits following topical PDT for benign skin conditions such as acne vulgaris, viral warts, and photorejuvenation without causing severe side effects.

Current evidence and applications of photodynamic therapy in dermatology

In photodynamic therapy (PDT) a photosensitizer – a molecule that is activated by light – is administered and exposed to a light source. This leads both to destruction of cells targeted by the particular type of photosensitizer, and immunomodulation. Given the ease with which photosensitizers and light can be delivered to the skin, it should come as no surprise that PDT is an increasingly utilized therapeutic in dermatology. PDT is used commonly to treat precancerous cells, sun-damaged skin, and acne. It has reportedly also been used to treat other conditions including inflammatory disorders and cutaneous infections. This review discusses the principles behind how PDT is used in dermatology, as well as evidence for current applications of PDT.

Photodynamic therapy with topical aminolevulinic acid

Photodynamic therapy (PDT) is a relatively new therapy in dermatology that uses the topical application of a porphyrin derivative to selectively destroy a cutaneous target. The action is implemented by the application of a specific light frequency. The ability of porphyrin to selectively target tumor tissue has been known since the 1960s. In the late 1970s, the underlying mechanism was defined, and Dougherty’s discovery of the first chromophore led to the production and commercialization of Photofrin^®. Many other chromophores that can act as photosensitizers have been studied since then, with aminolevulinic acid currently the most commonly used chromophore in clinical practice. PDT is simple, minimally invasive and can be administered on an outpatient basis. The efficacy of PDT has been proven for actinic keratosis, Bowen’s disease and basal cell carcinoma; another of its well-known applications is the treatment of photoaging. Indications for its use are continuously increasing, and promising results are reported for various skin diseases. In this paper we report the mechanism of action of PDT with aminolevulinic acid, the literature concerning the most common diseases treated with PDT and the subsequent level of evidence.

Topical treatments for cutaneous warts

BACKGROUND

Viral warts are a common skin condition, which can range in severity from a minor nuisance that resolve spontaneously to a troublesome, chronic condition. Many different topical treatments are available.

OBJECTIVES

To evaluate the efficacy of local treatments for cutaneous non-genital warts in healthy, immunocompetent adults and children.

SEARCH METHODS

We updated our searches of the following databases to May 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 2005), EMBASE (from 2010), AMED (from 1985), LILACS (from 1982), and CINAHL (from 1981). We searched reference lists of articles and online trials registries for ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of topical treatments for cutaneous non-genital warts.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials and extracted data; a third author resolved any disagreements.

MAIN RESULTS

We included 85 trials involving a total of 8815 randomised participants (26 new studies were included in this update). There was a wide range of different treatments and a variety of trial designs. Many of the studies were judged to be at high risk of bias in one or more areas of trial design.Trials of salicylic acid (SA) versus placebo showed that the former significantly increased the chance of clearance of warts at all sites (RR (risk ratio) 1.56, 95% CI (confidence interval) 1.20 to 2.03). Subgroup analysis for different sites, hands (RR 2.67, 95% CI 1.43 to 5.01) and feet (RR 1.29, 95% CI 1.07 to 1.55), suggested it might be more effective for hands than feet.A meta-analysis of cryotherapy versus placebo for warts at all sites favoured neither intervention nor control (RR 1.45, 95% CI 0.65 to 3.23). Subgroup analysis for different sites, hands (RR 2.63, 95% CI 0.43 to 15.94) and feet (RR 0.90, 95% CI 0.26 to 3.07), again suggested better outcomes for hands than feet. One trial showed cryotherapy to be better than both placebo and SA, but only for hand warts.There was no significant difference in cure rates between cryotherapy at 2-, 3-, and 4-weekly intervals.Aggressive cryotherapy appeared more effective than gentle cryotherapy (RR 1.90, 95% CI 1.15 to 3.15), but with increased adverse effects.Meta-analysis did not demonstrate a significant difference in effectiveness between cryotherapy and SA at all sites (RR 1.23, 95% CI 0.88 to 1.71) or in subgroup analyses for hands and feet.Two trials with 328 participants showed that SA and cryotherapy combined appeared more effective than SA alone (RR 1.24, 95% CI 1.07 to 1.43).The benefit of intralesional bleomycin remains uncertain as the evidence was inconsistent. The most informative trial with 31 participants showed no significant difference in cure rate between bleomycin and saline injections (RR 1.28, 95% CI 0.92 to 1.78).Dinitrochlorobenzene was more than twice as effective as placebo in 2 trials with 80 participants (RR 2.12, 95% CI 1.38 to 3.26).Two trials of clear duct tape with 193 participants demonstrated no advantage over placebo (RR 1.43, 95% CI 0.51 to 4.05).We could not combine data from trials of the following treatments: intralesional 5-fluorouracil, topical zinc, silver nitrate (which demonstrated possible beneficial effects), topical 5-fluorouracil, pulsed dye laser, photodynamic therapy, 80% phenol, 5% imiquimod cream, intralesional antigen, and topical alpha-lactalbumin-oleic acid (which showed no advantage over placebo).We did not identify any RCTs that evaluated surgery (curettage, excision), formaldehyde, podophyllotoxin, cantharidin, diphencyprone, or squaric acid dibutylester.

AUTHORS' CONCLUSIONS

Data from two new trials comparing SA and cryotherapy have allowed a better appraisal of their effectiveness. The evidence remains more consistent for SA, but only shows a modest therapeutic effect. Overall, trials comparing cryotherapy with placebo showed no significant difference in effectiveness, but the same was also true for trials comparing cryotherapy with SA. Only one trial showed cryotherapy to be better than both SA and placebo, and this was only for hand warts. Adverse effects, such as pain, blistering, and scarring, were not consistently reported but are probably more common with cryotherapy.None of the other reviewed treatments appeared safer or more effective than SA and cryotherapy. Two trials of clear duct tape demonstrated no advantage over placebo. Dinitrochlorobenzene (and possibly other similar contact sensitisers) may be useful for the treatment of refractory warts.

Photodynamic therapy for infections: clinical applications

BACKGROUND AND OBJECTIVE

Photodynamic therapy (PDT) was discovered over 100 years ago by its ability to kill various microorganisms when the appropriate dye and light were combined in the presence of oxygen. However it is only in relatively recent times that PDT has been studied as a treatment for various types of localized infections. This resurgence of interest has been partly motivated by the alarming increase in drug resistance amongst bacteria and other pathogens. This review will focus on the clinical applications of antimicrobial PDT.

STUDY DESIGN/MATERIALS AND METHODS

The published peer-reviewed literature was reviewed between 1960 and 2011.

RESULTS

The basics of antimicrobial PDT are discussed. Clinical applications of antimicrobial PDT to localized viral infections caused by herpes and papilloma viruses, and nonviral dermatological infections such as acne and other yeast, fungal and bacterial skin infections are covered. PDT has been used to treat bacterial infections in brain abscesses and non-healing ulcers. PDT for dental infections including periodontitis and endodontics has been well studied. PDT has also been used for cutaneous Leishmaniasis. Clinical trials of PDT and blue light alone therapy for gastric Helicobacter pylori infection are also covered.

CONCLUSION

As yet clinical PDT for infections has been mainly in the field of dermatology using 5-aminolevulanic acid and in dentistry using phenothiazinium dyes. We expect more to see applications of PDT to more challenging infections using advanced antimicrobial photosensitizers targeted to microbial cells in the years to come.

Successful Treatment of Plantar Warts with Very Diluted Bleomycin Using a Translesional Multipuncture Technique: Pilot Prospective Study

Background:

Plantar warts are common and often painful. Treatment of plantar warts is difficult and requires multiple treatments. Several clinical trials have proven the efficacy of bleomycin, but relatively high concentrations have been required and considerable side effects have been experienced.

Objective:

To evaluate the efficacy and safety of low-concentration (0.1 U/mL) bleomycin using a translesional injection technique for the treatment of plantar warts.

Methods:

The study included 23 patients with single or multiple plantar warts. Very low-concentration bleomycin was injected into a single wart or the largest plantar wart in the case of multiple lesions. Injections were performed at 4-week intervals until resolution of the warts or development of side effects. The translesional multipuncture technique was used.

Results:

Thirteen patients were male (56.5%), and the mean age was 27.7 years. The results revealed complete clearance of warts in 17 of 23 (74%) patients, partial response in 1 (4.3%) patient, and no response in 3 (13%) patients. Recurrence was observed in 2 patients at 3 months of follow-up. Among those two, one patient showed complete clearance after the second injection at 6 months of follow-up. All patients were followed for 6 months after the initial treatment. No significant long-term adverse effects were noted. Only three patients (13%) had localized moderate pain for 2 to 3 days after the injection.

Conclusion:

Translesional injection by very low-concentration (0.1 U/mL) bleomycin appears to be a simple, effective, and safe treatment modality for plantar warts.

Treatment of cutaneous warts: an evidence-based review

Cutaneous warts are common skin lesions caused by human papillomavirus infection. Treatment is aimed at relieving the patient's physical and psychological discomfort and at preventing the spread of infection by autoinoculation. Among the available medical and destructive therapeutic options for cutaneous warts, none is uniformly effective or virucidal. Moreover, in most cases their safety and efficacy has not been assessed in double-blind, controlled clinical trials, so that the reproducibility of many of the listed treatments is difficult to evaluate and a possible placebo effect cannot be ruled out. The aim of this article is to describe the outcome of current therapies for each clinical wart type according to evidence-based medicine studies published in the literature. For each clinical form, the existing treatments are classified as first-, second-, and third-line therapy. First-line therapy includes medical treatments (salicylic acid, silver nitrate, glutaraldehyde) that are useful to treat a single wart or a few and/or small common warts of short duration (less than 1 year). If these treatments have failed or are contraindicated, cryotherapy may be considered as second-line therapy. For recurrent or difficult-to-treat lesions, third-line therapy includes a variety of alternative therapeutic options (topical, intralesional, systemic, and physical destruction) that are generally off-label (not US FDA approved), and whose use is limited by drawbacks or adverse effects. From pooled evidence-based medicine data, it is possible to conclude that significantly higher remission rates may be expected only with cryotherapy and salicylic acid used in combination.

Photodynamic therapy can improve warts' discomfort in renal transplant patients prospective multicenter study

Many studies have been conducted showing that aminolevulinic acid (ALA)-photodynamic therapy (PDT) can be an alternative treatment for recalcitrant warts. Recently, we performed a study evaluating methyl-aminolevulinic acid (MAL)-PDT for the treatment of hand warts in a population of renal transplant patients. Two symmetrical targets were selected on each hand and randomly assigned to chemical keratolytic treatment followed by three cycles of ALA-PDT (75 J cm(-2) red light). Patients were evaluated after 3 months and a second run of PDT was performed if the total area and number of warts decreased less than 50%, with evaluation every 3 months for 1 year. Twenty patients were included and 16 were evaluable (9 M, 7 F). After 6 months the reduction of warts' area was 48.4% on the treated side versus 18.4% in the control area (P = 0.021). The decrease in the total number of warts was 41%versus 19.4% (P = NS). The global tolerance of the treatment was good with acceptable pain during irradiation. These results suggest that ALA-PDT is a safe and efficient treatment for transplanted patient warts. The improvement between treated and control zone is 20% due to the decrease in untreated warts' area and number.

Efficiency of photodynamic therapy in the treatment of diffuse facial viral warts in an immunosuppressed patient: towards a gold standard?

A 64-year-old man with a pulmonary transplant developed diffuse verrucae vulgares of the neck. After the failure of multiple cryotherapy treatments, 3 sessions of photodynamic therapy resulted in rapid therapeutic clinical success. This moderately painful and well-tolerated treatment is reproducible and can be very useful in treating papillomavirus infections in the immunosuppressed patient.

The role of porphyrin chemistry in tumor imaging and photodynamic therapy

In recent years several review articles and books have been published on the use of porphyrin-based compounds in photodynamic therapy (PDT). This critical review is focused on (i) the basic concept of PDT, (ii) advantages of long-wavelength absorbing photosensitizers (PS), (iii) a brief discussion on recent advances in developing PDT agents, and (iv) the various synthetic strategies designed at the Roswell Park Cancer Institute, Buffalo, for developing highly effective long-wavelength PDT agents and their utility in constructing the conjugates with tumor-imaging and therapeutic potential (Theranostics). The clinical status of certain selected PDT agents is also summarized (205 references).

Photodynamic therapy for localized infections--state of the art

Photodynamic therapy (PDT) was discovered over 100 years ago by observing the killing of microorganisms when harmless dyes and visible light were combined in vitro. Since then it has primarily been developed as a treatment for cancer, ophthalmologic disorders and in dermatology. However, in recent years interest in the antimicrobial effects of PDT has revived and it has been proposed as a therapy for a large variety of localized infections. This revival of interest has largely been driven by the inexorable increase in drug resistance among many classes of pathogen. Advantages of PDT include equal killing effectiveness regardless of antibiotic resistance, and a lack of induction of PDT resistance. Disadvantages include the cessation of the antimicrobial effect when the light is turned off, and less than perfect selectivity for microbial cells over host tissue. This review will cover the use of PDT to kill or inactivate pathogens in ex vivo tissues and in biological materials such as blood. PDT has been successfully used to kill pathogens and even to save life in several animal models of localized infections such as surface wounds, burns, oral sites, abscesses and the middle ear. A large number of clinical studies of PDT for viral papillomatosis lesions and for acne refer to its antimicrobial effect, but it is unclear how important this microbial killing is to the overall therapeutic outcome. PDT for periodontitis is a rapidly growing clinical application and other dental applications are under investigation. PDT is being clinically studied for other dermatological infections such as leishmaniasis and mycobacteria. Antimicrobial PDT will become more important in the future as antibiotic resistance is only expected to continue to increase.

Terapia fotodinâmica em dermatologia: princípios básicos e aplicações

A terapia fotodinâmica envolve a administração de uma droga fotossensibilizante e sua ativação subsequente pela luz de comprimento de onda correspondente ao espectro de absorção do fotossensibilizador. Atualmente, a terapia fotodinâmica tópica é aprovada para o tratamento de condições oncológicas cutâneas como queratoses actínicas, doença de Bowen e carcinoma basocelular superficial em diversos países do mundo. Estudos multicêntricos controlados e randomizados demonstram a alta eficácia e resultado cosmético final superior dessa modalidade terapêutica em relação aos tratamentos convencionais. Para condições cutâneas não oncológicas, como acne vulgar, verrugas virais e esclerodermia localizada, há também relatos e série de casos confirmando o potencial terapêutico da terapia fotodinâmica. O desenvolvimento de fotossensibilizantes tópicos, ácido 5-aminolevulínico (ALA) ou seu metiléster (MAL), frente aos derivados da hematoporfirina de aplicação sistêmica, permitiu um grande avanço na popularidade da TFD na dermatologia, uma vez que tanto ALA quanto MAL tópicos não induzem mais fotossensibilidade generalizada prolongada. A produção de intermediários reativos de oxigênio, como oxigênio singlet, depende da concentração, da localização do fotossensibilizante no tecido alvo, assim como da dose de luz utilizada. Tanto as lâmpadas de amplo espectro quanto os LEDs (do inglês light emitting diodes) constituem fontes de luz adequadas para que os efeitos citotóxicos da terapia fotodinâmica resultem na destruição do tumor ou seus efeitos imunomodulatórios atuem melhorando as condições inflamatórias cutâneas.

Treatment of Verrucae Vulgaris and Molluscum Contagiosum with Photodynamic Therapy

The use of 5-aminolevulinc acid photodynamic therapy in the treatment of recalcitrant verrucae vulgaris and in the treatment of recalcitrant molluscum contagiosum has been shown to substantially reduce the lesion count and severity. Clinical research published in the medical literature and personal experience of both of the authors support the use of 5-aminolevulinc acid photodynamic therapy in appropriate individuals with recalcitrant verrucae vulgaris and molluscum contagiosum lesions. This article reviews the medical literature and identifies the various lasers and lights sources used to treat these conditions.

Pain induced by photodynamic therapy of warts

BACKGROUND

Photodynamic therapy with topical 5-aminolevulinic acid (ALA), followed by irradiation with red light (ALA-PDT), is used for non-melanoma skin cancer and other dermatological diseases. Pain during and after light exposure is a well-known adverse advent that may be a limiting factor for treatment, particularly, in viral warts.

METHODS

To assess the pain induced by ALA-PDT, we asked 45 patients enrolled in a randomized, placebo-controlled trial with six consecutive ALA- and placebo-PDT treatments for recalcitrant foot and hand warts to fill in questionnaires about pain immediately and 24 h after each treatment.

RESULTS

Immediately and 24 h after each of the six treatments, pain intensity was significantly higher in warts treated with ALA-PDT than in warts treated with placebo-PDT (P<0.028). Severe or unbearable pain was reported from a median of 17% (6-31%) of the ALA -treated warts and from a median of 2% (0-15%) from the placebo-treated warts immediately after the treatments. With increasing treatments, no significant change in pain intensity was observed and no significant relation was found between the pain intensity and the relative change in wart area. The pain was primarily characterized as burning and shooting. The pain lasted about 30 h (range: 1-96 h).

CONCLUSION

We conclude that pain induced by ALA-PDT is of such intensity in about one-fifth of the warts that pain relief is indicated.

An armamentarium of wart treatments

Patients and clinicians experience the frustration of cutaneous viral warts caused by infection with the human papilloma virus (HPV).Warts appear in various forms on different sites of the body and include common warts (verruca vulgaris), plane or flat warts, myrmecia, plantar warts, coalesced mosaic warts, filiform warts, periungual warts, anogenital warts (venereal or condyloma acuminata), oral warts and respiratory papillomas. Cervical infection with HPV is now known to cause cervical cancer if untreated. A review of the medical literature reveals a huge armamentarium of wart monotherapies and combination therapies. Official evidence-based guidelines exist for the treatment of warts, but very few of the reported treatments have been tested by rigorous blinded, randomized controlled trials.Therefore, official recommendations do not often include treatments with reportedly high success rates, but they should not be ignored when considering treatment options. It is the purpose of this review to provide a comprehensive overview of the wart treatment literature to expand awareness of the options available to practitioners faced with patients presenting with problematic warts.

Comparison between the efficacy of photodynamic therapy and topical paromomycin in the treatment of Old World cutaneous leishmaniasis: a placebo-controlled, randomized clinical trial

BACKGROUND

The optimal treatment for cutaneous leishmaniasis (CL) is not known. Topical paromomycin is one of the many drugs that have been suggested for the treatment of CL caused by Leishmania major. Recently, topical photodynamic therapy (PDT) has been reported to be effective in the treatment of CL.

AIMS

To compare the parasitological and clinical efficacy of PDT vs. topical paromomycin in patients with Old World CL caused by L. major in Iran.

METHODS

In this trial, 60 patients with the clinical and parasitological diagnosis of CL were recruited and were randomly divided into three treatment groups of 20 subjects each. Group 1 was treated with weekly topical PDT, and groups 2 and 3 received twice-daily topical paromomycin and placebo, respectively. The duration of treatment was 4 weeks for all groups. These groups were followed for 2 months after the end of treatment.

RESULTS

In total, 57 patients with 95 lesions completed the study. At the end of the study, complete improvement was seen in 29 of 31 (93.5%), 14 of 34 (41.2%) and 4 of 30 lesions (13.3%) in groups 1, 2 and 3, respectively (P<0.001). At the same time point, 100%, 64.7% and 20% of the lesions had parasitological cure in group 1, 2 and 3, respectively (P<0.001).

CONCLUSION

Topical PDT can be used safely as a rapid and highly effective alternative treatment choice for Old World CL in selected patients.

Topical treatments for cutaneous warts

BACKGROUND

Viral warts are common and usually harmless but very troublesome. A very wide range of local treatments are used.

OBJECTIVES

To assess the effects of different local treatments for cutaneous, non-genital warts in healthy people.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (March 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005), MEDLINE (1966 to March 2005), EMBASE (1980 to March 2005) and a number of other biomedical databases. The references of all trials and selected review articles were also searched. In addition, we contacted pharmaceutical companies involved in local treatments for warts and experts in the field

SELECTION CRITERIA

Randomised controlled trials of local treatments for cutaneous non-genital viral warts in immunocompetent (healthy) people.

DATA COLLECTION AND ANALYSIS

Data was extracted and two authors independently selected the trials and assessed methodological quality.

MAIN RESULTS

Sixty trials were identified that fulfilled the criteria for inclusion. The evidence provided by these studies was generally weak due to poor methodology and reporting. In 21 trials with placebo groups that used participants as the unit of analysis, the average cure rate of placebo preparations was 27% (range 0 to 73%) after an average period of 15 weeks (range 4 to 24 weeks). The best available evidence was for simple topical treatments containing salicylic acid, which were clearly better than placebo. Data pooled from five placebo-controlled trials showed a cure rate of 117/160 (73%) compared with 78/162 (48%) in controls, which translates to a risk ratio of 1.60 (95% confidence interval 1.16 to 2.23), using a random effects model. Evidence for the absolute efficacy of cryotherapy was surprisingly lacking. Two trials comparing cryotherapy with salicylic acid and one comparing duct tape with cryotherapy showed no significant difference in efficacy. Evidence for the efficacy of the remaining treatments reviewed was limited.

AUTHORS' CONCLUSIONS

There is a considerable lack of evidence on which to base the rational use of topical treatments for common warts. The reviewed trials are highly variable in method and quality. Cure rates with placebo preparations are variable but nevertheless considerable. There is certainly evidence that simple topical treatments containing salicylic acid have a therapeutic effect. There is less evidence for the efficacy of cryotherapy, but reasonable evidence that it is only of equivalent efficacy to simpler and safer treatments. The benefits and risks of topical dinitrochlorobenzene and 5-fluorouracil, intralesional bleomycin and interferons, photodynamic therapy and other miscellaneous treatments remain to be determined.