Photodynamic therapy for dermatologic conditions in the pediatric population: a literature review

Ionic Liquid Pretreatment Enhances Skin Penetration of 5-Aminolevulinic Acid: A Promising Scheme for Photodynamic Therapy for Acne Vulgaris

Acne vulgaris is one of the most prevalent skin disorders; it affects up to 85% of adolescents and often persists into adulthood. Topical 5-aminolevulinic acid (ALA)-based photodynamic therapy (PDT) provides an alternative treatment for acne; however, its efficacy is greatly undermined by the limited skin permeability of ALA. Herein, biocompatible ionic liquids (ILs) based on aliphatic acid/choline were employed to enhance the dermal delivery of ALA, thereby improving the efficacy of PDT. In addition to the one-step delivery of ALA by utilizing ILs as carriers, a two-step strategy of pretreating the skin with blank ILs, followed by the administration of free ALA, was employed to test the IL-facilitated dermal delivery of ALA in vitro. The cumulative permeation of ALA through the excised rat skin after IL pretreatment was significantly greater than that in the untreated group, the 20% dimethyl sulfoxide (DMSO) penetration enhancer group, and the one-step group. The penetration efficiency was influenced by formulation and treatment factors, including the type of IL, pretreatment duration, water content in the ILs, and concentration of ALA. In rats, IL pretreatment facilitated faster, greater, and deeper ALA-induced protoporphyrin IX (PpIX) accumulation. Moreover, the IL pretreatment regimen significantly improved the efficacy of ALA-based PDT against acne vulgaris in a rat ear model. The model IL choline citrate ([Ch]3[Cit]1) had a moderate effect on the skin barrier. Trans-epidermal water loss could be recovered 1 h after IL treatment, but no irritation to the rat skin was detected after 7 days of consecutive treatment. It was concluded that biocompatible IL pretreatment enhances the penetration of ALA and thus facilitates the transformation of PpIX and improves the efficacy of PDT against acne vulgaris.

Photodynamic therapy for malignant brain tumors in children and young adolescents

Photodynamic therapy (PDT) targets tumor cell remnants after resection. Here, we evaluated the feasibility of PDT for malignant brain tumors in children and young adolescents. This was a single-center, non-randomized, phase I/II clinical study. The primary endpoints were the safety of treatment with talaporfin sodium (TS) (phase I) and overall survival (OS) after PDT (phase II). The secondary endpoint was progression-free survival (PFS) after PDT. The TS dose was determined by dose escalation from 10 to 20 to 40 mg/m² for every three cases starting from the initial enrolled case. Eight patients with a mean age of 170.2 months (129-214 months) at the time of PDT received nine procedures with a mean follow-up duration of 16.8 months (1-42 months) after PDT. Histopathological diagnoses included supratentorial anaplastic ependymoma (n = 2), anaplastic astrocytoma (n = 1), diffuse midline glioma with H3K27M mutation (n = 1), glioblastoma (n = 3), and pediatric high-grade glioma (n = 1). The outcome was survival in five patients and death in three patients. Recurrence occurred in six of the eight patients; the remaining two were recurrence-free after PDT. Therefore, OS and PFS were calculated as 21 and 6 months, respectively. Seizures and fevers, which were likely surgery-related symptoms, were commonly observed. Photosensitive skin rashes or liver dysfunction, which are common adverse effects in adults, were not observed. Our results showed that TS can be used safely in children at doses comparable to those used in adults, as there was no major complication associated with TS administration. However, we cannot make a definitive conclusion about the efficacy of PDT because of the small number of participants. Accumulating cases was difficult because of the rarity of pediatric brain tumors and the difficulty in making a preoperative differential diagnosis, considering the wide range of histopathological findings. Moreover, the psychological stress associated with light-shielding management in pediatric patients was more severe than initially expected. In conclusion, TS at doses comparable to those used in adults may be safe for use in children and young adolescents between the ages of 6 and 20 years. However, further studies are needed to clarify its efficacy.

Photodynamic Therapy in Complex Therapy of Retroperitoneal Tumors in Children

During the period from 2009 to 2021, 93 patients aged 0–11 years (48 boys and 45 girls) with retroperitoneal tumors were treated. There were 66 patients with nephroblastoma and 27 patients with adrenal neuroblastoma among them. As per treatment strategies, the patients were separated into two groups: the control group and the study group. The control group (comparison) received therapy according to the protocols, whereas the study group consisted of patients who received photodynamic therapy (PDT) in addition to the standard treatment. The control group consists of 47 patients with retroperitoneal tumors, including 35 patients with nephroblastoma and 12 patients with adrenal neuroblastoma. The study group included 46 children: 31 patients with nephroblastoma and 15 patients with adrenal neuroblastoma. The 5-year survival rate in the control group was 74.5%, and it was 91.3% in the study group (p = 0.030). Recurrent tumors developed in 14.9% of the patients in the control group, while in the study group, relapse occurred in 8.7% of the patients (p = 0.357). The PDT used in this study for treatment of retroperitoneal tumors improves the results of surgical treatment. It also appreciably increases the survival rate of patients with retroperitoneal tumors. Overall, PDT is a hopeful antitumor approach and can be effectively used in the complex therapy of retroperitoneal tumors in children.

Photodynamic Therapy for Treatment of Disease in Children—A Review of the Literature

Photodynamic therapy is a mode of treatment whereby local irradiation of an administered photosensitizer with light of a specific wavelength generates cytotoxic reactive oxygen species. Despite the upward trend in the popularity of this method in adults, it is not yet commonly used in the treatment of children. Due to certain limitations, underdeveloped treatment regimens and potential side effects, the use of photodynamic therapy in the pediatric population is still in the initial phases of evaluation in clinical trials. Method: This study is a review of articles in English from the databases PubMed and Web of Science retrieved by applying the search term “photodynamic therapy in children” from 2000–2020. Results: Based on the literature review, we analyze selected pediatric clinical cases in which photodynamic therapy was used for treatment in children. Examples of photodynamic therapy for treatment of dermatological diseases, diseases of the mucosa of the upper respiratory tract, halitosis, eye diseases and brain tumors are described. The paper describes the effectiveness of anti-cancer photodynamic therapy, including its use in antibacterial therapy. Conclusions: The results of the analysis suggest the potential of photodynamic therapy for the treatment of various diseases in children.

Successful Application of Aminolevulinic Acid/Photodynamic Therapy in the Treatment of Condyloma Acuminatum in a Young Child

BACKGROUND

Condyloma acuminatum is a benign proliferative lesion of the genitalia and perianal region caused by human papillomavirus infection, which is rare in children. Traditional treatments include topical medications, CO₂ laser therapy, cryotherapy, and surgical resection, which are often associated with pain, scarring, and recurrence. In recent years, aminolevulinic acid/photodynamic therapy has been applied as a new method for treating condyloma acuminatum in adults. However, its application in young children is limited. We herein report a case of condyloma acuminatum treated by aminolevulinic acid/photodynamic therapy in a young boy.

CASE REPORT

The patient was a 2-year-old boy who presented with a 10-day history of warty masses on his glans penis. Condyloma acuminatum was diagnosed based on skin lesions and histological findings. Aminolevulinic acid/photodynamic therapy was selected as the treatment method after obtaining informed consent from his guardians. We performed five rounds with a treatment interval of 7 days and achieved a complete disappearance of the skin lesions without chapping, flushing, or scarring. There was no recurrence during the 6-month follow-up period.

CONCLUSION

Photodynamic therapy can be used as an alternative treatment for condyloma acuminatum in young children. More case studies are needed to confirm the value of this treatment.

A case of pediatric lymphomatoid papulosis treated with photodynamic therapy and narrowband ultraviolet B

We report a case of a 13-year-old boy with extensive lymphomatoid papulosis (LyP) involving his elbows, forearms, proximal thighs, and right hip, with treatment-resistant nodules on his right forearm. He was treated with full-body narrowband ultraviolet B and targeted photodynamic therapy (PDT) with 20% aminolevulinic acid (ALA). After two months, there was complete resolution of the right forearm nodules. Due to its minimal toxicity, PDT offers unique advantages and may be considered for pediatric LyP patients with symptomatic, localized disease resistant to conventional treatments.

Efficacy and safety of conventional versus daylight photodynamic therapy in children affected by multiple facial flat warts

BACKGROUND

facial flat warts (FFWs) are a superficial viral skin disease, extremely common in childhood. Recently, conventional photodynamic therapy (C-PDT) has been used for the treatment of FFWs with good outcome. The efficacy of daylight photodynamic therapy (DL-PDT) has not yet been evaluated.

OBJECTIVES

to investigate and assess the efficacy and safety of C-PDT versus DL-PDT using 10% aminolevulinic acid (ALA) in the treatment of recalcitrant FFWs in a paediatric setting.

MATERIALS AND METHODS

30 consecutive patients aged <18 years with FFWs of the face were included and randomly divided into two groups: group A (15 patients) was treated with C-PDT and group B (15 patients) with DL-PDT. Patients underwent treatments for three times with 1-month intervals. The response was assessed on week 4,812 and 24 (T4,T8,T12,T24) and scored as excellent (75-100% reduction of total wart count), very good (74-50% reduction), good (49-25% reduction), poor (<25% reduction or no response). Any adverse event occurring during/after ALA application/irradiation as well as pain intensity were recorded at each visit.

RESULTS

at T4 and T8 no excellent response was achieved in both groups. At week 12, excellent response was observed in 53.3% of group A patients vs 0% of group B patients, although in the latter 66.7% of patients achieved a very good response. Excellent outcome raised to 73.3% and 80% in group A and B, respectively, at week 24. Poor response to therapy was observed in 26.7% of patients in group A and 20% in group B. Both treatment modalities were well tolerated, with transient pain, irritation and hyperpigmentation as main side effects.

CONCLUSIONS

ALA-PDT is effective and safe for FFWs, with striking cosmetic results and no recurrence. Compared with conventional modality, DL-PDT is better tolerated, time-saving, nearly painless and greatly appreciated by young patients.

Mitochondrial Oxygen Monitoring During Surgical Repair of Congenital Diaphragmatic Hernia or Esophageal Atresia: A Feasibility Study

Current monitoring techniques in neonates lack sensitivity for hypoxia at cellular level. The recent introduction of the non-invasive Cellular Oxygen METabolism (COMET) monitor enables measuring in vivo mitochondrial oxygen tension (mitoPO₂), based on oxygen-dependent quenching of delayed fluorescence of 5-aminolevulinic acid (ALA)-enhanced protoporphyrin IX. The aim is to determine the feasibility and safety of non-invasive mitoPO₂ monitoring in surgical newborns. MitoPO₂ measurements were conducted in a tertiary pediatric center during surgical repair of congenital diaphragmatic hernia or esophageal atresia. Intraoperative mitoPO₂ monitoring was performed with a COMET monitor in 11 congenital diaphragmatic hernia and four esophageal atresia neonates with the median age at surgery being 2 days (IQR 1.25-5.75). Measurements were done at the skin and oxygen-dependent delayed fluorescence was measurable after at least 4 h application of an ALA plaster. Pathophysiological disturbances led to perturbations in mitoPO₂ and were not observed with standard monitoring modalities. The technique did not cause damage to the skin, and seemed safe in this respect in all patients, and in 12 cases intraoperative monitoring was successfully completed. Some external and potentially preventable factors-the measurement site being exposed to the disinfectant chlorohexidine, purple skin marker, or infrared light-seemed responsible for the inability to detect an adequate delayed fluorescence signal. In conclusion, this is the first study showing it is possible to measure mitoPO₂ in neonates and that the cutaneous administration of ALA to neonates in the described situation can be safely applied. Preliminary data suggests that mitoPO₂ in neonates responds to perturbations in physiological status.

A review of BF-200 ALA for the photodynamic treatment of mild-to-moderate actinic keratosis

BF-200 ALA is a combination of a nanoscale-lipid vesicle formulation and the prodrug 5-aminolevulinic acid (5-ALA). The nanoemulsion stabilizes the prodrug and enhances its penetration through the stratum corneum. It has shown excellent therapeutic results in both lesion and field-directed photodynamic therapy of actinic keratosis (AK). AK is an early form of epidermal neoplasia and a precursor of invasive cutaneous squamous cell carcinoma. It is characterized by the combination of visible neoplastic lesions and surrounding tissue also harboring tumorigenic UV-induced mutations: a concept called field cancerization. A selective, field-directed treatment is ideal to meet the requirements of field change. Here, we review the clinical data on BF-200 ALA for AK along with a summary of molecular mechanisms and future perspectives.