The effects of infrared radiation on the human skin.

BACKGROUND: Infrared radiation (IR) is the portion of the electromagnetic spectrum between visible light (VL) and microwaves, with wavelengths between 700 nm and 1 mm. Humans are mainly exposed to ultraviolet (UV) radiation (UVR) and IR through the sun. Unlike UVR which is well known for its carcinogenic properties, the relationship between IR and skin health has not been as extensively studied; as such, we gather the available published evidence here to better elucidate this relationship. METHODS: Several databases including Pubmed, Google Scholar, and Embase were searched for articles relating to infrared radiation and the skin. Articles were selected for their relevance and novelty. RESULTS: Detrimental effects such as thermal burns, photocarcinogenesis, and photoaging have been reported, though evidence suggests that these may be due to the thermal effects produced secondary to IR exposure rather than the isolated effect of IR. There are currently no chemical or physical filters specifically available for protection against IR, and existing compounds are not known to have IR-filtering capacity. Interestingly, IR may have some photoprotective properties against the carcinogenic effects of UVR. Furthermore, IR has been used with encouraging results in skin rejuvenation, wound healing, and hair restoration when given at an appropriate therapeutic dose. CONCLUSION: A better understanding of the current landscape of research surrounding IR can help illuminate its effects on the skin and highlight areas for further research. Here, we review relevant data on IR to assess its deleterious and beneficial effects on human skin, along with possible means for IR photoprotection.

Spectrum of virucidal activity from ultraviolet to infrared radiation.

The COVID-19 pandemic has sparked a demand for safe and highly effective decontamination techniques for both personal protective equipment (PPE) and hospital and operating rooms. The gradual lifting of lockdown restrictions warrants the expansion of these measures into the outpatient arena. Ultraviolet C (UVC) radiation has well-known germicidal properties and is among the most frequently reported decontamination techniques used today. However, there is evidence that wavelengths beyond the traditional 254 nm UVC - namely far UVC (222 nm), ultraviolet B, ultraviolet A, visible light, and infrared radiation - have germicidal properties as well. This review will cover current literature regarding the germicidal effects of wavelengths ranging from UVC through the infrared waveband with an emphasis on their activity against viruses, and their potential applicability in the healthcare setting for general decontamination during an infectious outbreak.

Melanoma Biomarkers and Their Potential Application for In Vivo Diagnostic Imaging Modalities.

Melanoma is the deadliest form of skin cancer and remains a diagnostic challenge in the dermatology clinic. Several non-invasive imaging techniques have been developed to identify melanoma. The signal source in each of these modalities is based on the alteration of physical characteristics of the tissue from healthy/benign to melanoma. However, as these characteristics are not always sufficiently specific, the current imaging techniques are not adequate for use in the clinical setting. A more robust way of melanoma diagnosis is to "stain" or selectively target the suspect tissue with a melanoma biomarker attached to a contrast enhancer of one imaging modality. Here, we categorize and review known melanoma diagnostic biomarkers with the goal of guiding skin imaging experts to design an appropriate diagnostic tool for differentiating between melanoma and benign lesions with a high specificity and sensitivity.

Pemetrexed-Induced Pseudocellulitis: A Diagnostic Conundrum.

Pemetrexed, an anti-folate, antineoplastic agent, effectively treats various malignancies such as non-small cell lung cancer (NSCLC) and mesothelioma. Here, we report two cases of recurrent pemetrexed-induced lower extremity erythema and edema, one in a 60-year-old male and the other in a 47-year-old male, who were both treated for recurrent cellulitis on multiple occasions before finally being diagnosed with pemetrexed-induced pseudocellulitis (PIP), a rarely reported adverse effect. This is an important diagnostic pitfall for clinicians to be aware of, as early recognition may minimize patient morbidity and prevent unnecessary hospitalization and antibiotic use for presumed cellulitis.

Challenging diagnosis of indolent systemic mastocytosis isolated to the GI tract.

Mastocytosis is a rare group of disorders that presents with heterogenous phenotypes depending on the organ system involved. In the absence of cutaneous involvement-mast cell aggregates that may present as papules, nodules or plaques-classically associated with indolent systemic mastocytosis (SM), the diagnosis of this rare condition is particularly challenging. When localised to the gastrointestinal (GI) tract, symptoms of indolent SM are often non-specific and mimic common conditions such as inflammatory bowel disease or irritable bowel syndrome. Diagnosis may be suspected by clinical presentation, but biopsy with histopathological analysis is necessary to confirm. We present a rare case of indolent SM without cutaneous features. In the absence of typical cutaneous features, indolent SM should be considered in the differential diagnosis of a patient with persistent GI symptoms refractory to medical treatment, as failure to do so can lead to delay in the appropriate diagnosis and treatment.

Acrokeratosis paraneoplastica (Bazex syndrome) as the presenting sign of pancreatic adenocarcinoma.

Acrokeratosis paraneoplastica (Bazex syndrome) is a rare paraneoplastic skin condition characterised by acral psoriasiform plaques, with a predilection for the nose, ears, hands and feet. It typically presents before the discovery of an internal malignancy and is often misdiagnosed as an inflammatory dermatitis that does not respond to treatment. It is associated with squamous cell carcinoma of the aerodigestive tract and lung, as well as adenocarcinoma of the lung, colon and gastrum. Here, we describe the second reported case of Bazex syndrome in the setting of pancreatic adenocarcinoma and the first such case in a patient of African ancestry.

Rare case of primary leiomyosarcoma of the breast treated with wide local excision and planned cosmetic breast reduction surgery.

Primary leiomyosarcoma of the breast is an extremely rare neoplasm accounting for less than 0.0006% of all breast malignancies, with fewer than 80 cases reported in the literature to date. Here, we present a case of leiomyosarcoma of the breast in a 61-year-old woman without traditional risk factors. This case was treated with lumpectomy requiring wide margins due to the high rate of local recurrence. A planned breast reduction surgery was deemed adequate postlumpectomy therapy to prevent cancer recurrence, negating the need for chemotherapy or radiation therapy. To our knowledge, this is the first case in which cosmetic breast reduction surgery will be used as postlumpectomy cancer recurrence risk mitigation for primary leiomyosarcoma of the breast. Patients with this malignancy have a relatively poor prognosis compared with other breast cancer types, with a 5-year disease-free survival of 33%-52%. As such, frequent follow-up and monitoring for postresection recurrence is essential.

Contrast-enhanced optical coherence tomography for melanoma detection: An in vitro study.

Optical coherence tomography (OCT), with a high-spatial resolution (<10 microns), intermediate penetration depth (~1.5 mm) and volumetric imaging capability is a great candidate to be used as a diagnostic-assistant modality in dermatology. At this time, the accuracy of OCT for melanoma detection is lower than anticipated. In this letter, we studied for the first time, the use of a novel contrast agent consist of ultra-small nanoparticles conjugated to a melanoma biomarker to improve the accuracy of OCT for differentiation of melanoma cells from nonmelanoma cells, in vitro. We call this approach SMall nanoparticle Aggregation-enhanced Radiomics of Tumor (SMART)-OCT imaging. This initial proof of concept study is the first step toward the broad utilization of this method for high accuracy all types of tumor detection applications.

Unilateral segmental Darier's disease associated with neuropsychiatric disorders.

Unilateral segmental Darier's disease (DD) is a rare variant of DD that presents with erythematic lesions in a unilateral distribution without other associated features of DD. Although diagnosis is challenging, unilateral segmental DD should be considered for an acantholytic dermatosis in a unilateral distribution and a history of neuropsychiatric disorders.

Vibration analysis of healthy skin: toward a noninvasive skin diagnosis methodology.

Several noninvasive imaging techniques have been developed to monitor the health of skin and enhance the diagnosis of skin diseases. Among them, skin elastography is a popular technique used to measure the elasticity of the skin. A change in the elasticity of the skin can influence its natural frequencies and mode shapes. We propose a technique to use the resonant frequencies and mode shapes of the skin to monitor its health. Our study demonstrates how the resonant frequencies and mode shapes of skin can be obtained using numerical and experimental analysis. In our study, natural frequencies and mode shapes are obtained via two methods: (1) finite element analysis: an eigensolution is performed on a finite element model of normal skin, including stratum corneum, epidermis, dermis, and subcutaneous layers and (2) digital image correlation (DIC): several in-vivo measurements have been performed using DIC. The experimental results show a correlation between the DIC and FE results suggesting a noninvasive method to obtain vibration properties of the skin. This method can be further examined to be eventually used as a method to differentiate healthy skin from diseased skin. Prevention, early diagnosis, and treatment are critical in helping to reduce the incidence, morbidity, and mortality associated with skin cancer; thus, making the current study significant and important in the field of skin biomechanics.

Development and Optimization of a Fluorescent Imaging System to Detect Amyloid-ß Proteins: Phantom Study.

Alzheimer disease is the most common form of dementia, affecting more than 5 million people in the United States. During the progression of Alzheimer disease, a particular protein begins to accumulate in the brain and also in extensions of the brain, ie, the retina. This protein, amyloid-ß (Aß), exhibits fluorescent properties. The purpose of this research article is to explore the implications of designing a fluorescent imaging system able to detect Aß proteins in the retina. We designed and implemented a fluorescent imaging system with a range of applications that can be reconfigured on a fluorophore to fluorophore basis and tested its feasibility and capabilities using Cy5 and CRANAD-2 imaging probes. The results indicate a promising potential for the imaging system to be used to study the Aß biomarker. A performance evaluation involving ex vivo and in vivo experiments is planned for future study.

Granular Cell Tumor Imaging Using Optical Coherence Tomography.

BACKGROUND: Granular cell tumor (GCT) is a relatively uncommon tumor that may affect the skin. The tumor can develop anywhere on the body, although it is predominately seen in oral cavities and in the head and neck regions. Here, we present the results of optical coherence tomography (OCT) imaging of a large GCT located on the abdomen of a patient. We also present an analytical method to differentiate between healthy tissue and GCT tissues. MATERIALS AND METHODS: A multibeam, Fourier domain, swept source OCT was used for imaging. The OCT had a central wavelength of 1305 ± 15 nm and lateral and axial resolutions of 7.5 and 10 µm, respectively. Qualitative and quantitative analyses of the tumor and healthy skin are reported. RESULTS: Abrupt changes in architectures of the dermal and epidermal layers in the GCT lesion were observed. These architectural changes were not observed in healthy skin. DISCUSSION: To quantitatively differentiate healthy skin from tumor regions, an optical attenuation coefficient analysis based on single-scattering formulation was performed. The methodology introduced here could have the capability to delineate boundaries of a tumor prior to surgical excision.