Mouse model of selective cryolipolysis.

BACKGROUND: Cryolipolysis is a noninvasive method of destroying adipocytes using controlled cooling, thereby enabling localized and targeted fat reduction. Due to their greater vulnerability to cold injury, adipocytes are selectively targeted, while other cell types are spared. OBJECTIVES: This study aims to develop a mouse model of cryolipolysis to offer a reliable and convenient alternative to human models, providing a methodology to validate clinical hypotheses in-depth with relative ease, low cost, and efficiency. This further facilitates comprehensive studies of the molecular mechanisms involved in cryolipolysis. MATERIALS AND METHODS: Mice (C57BL/6J) were placed under general anesthesia and were treated using our custom, miniaturized cryolipolysis system. A thermoelectric cooling probe was applied to the inguinal (ING) area for either a cold exposure of -10°C, or for a room temperature exposure for 10 minutes. The thickness of the subcutaneous fat of the mice was quantified using an optical coherence tomography (OCT) imaging system before and after the treatment. Histological analyses were performed before and after cryolipolysis at multiple time points. RESULTS: OCT analysis showed that mice that underwent cold cryolipolysis treatment induced a significantly greater reduction of subcutaneous fat thickness 1 month after treatment than the control mice. The mice that received cold treatment had no skin injuries. The selective damage of adipocytes stimulated cold panniculitis that was characterized histologically by infiltration of immune cells 2 and 3 days after treatment. CONCLUSION: This study shows that cryolipolysis performed in mice yields reproducible and measurable subcutaneous fat reduction, consistent with previous studies conducted in humans and pigs. Future studies can utilize the model of selective cryolipolysis developed by our group to further elucidate the cellular and molecular mechanisms of fat cell loss and improve clinical outcomes in humans.

Fluconazole-induced acute generalized exanthematous pustulosis.

Acute generalized exanthematous pustulosis (AGEP) is a rare severe cutaneous adverse reaction usually caused by drugs. The annual incidence is one to five cases per million. It is characterized by an acute febrile episode, accompanied by numerous small primarily non-follicular, sterile pustules arising within large areas of edematous erythema. There have been several case reports to date of AGEP following exposure to antifungals. Terbinafine is most commonly implicated in AGEP. We report a case of 7-year-old boy who developed AGEP shortly after commencing oral fluconazole for Tinea capitis. To our knowledge, this is the fourth reported case of AGEP due to fluconazole.

Mycoplasma pneumonia and atypical acute hemorrhagic edema of infancy.

Acute hemorrhagic edema of infancy is a benign rare presentation of leukocytoclastic vasculitis that affects children between 4 and 24 months of age. It usually involves the distal extremities, face, and ears. We report an atypical presentation of AHEI in a 1 year 5 months old boy starting initially over the trunk and back, then spreading to the face and extremities. Mycoplasma pneumonia IgM was found to be positive. The rash resolved spontaneously within two weeks. Herein we present a case of Mycoplasma induced AHEI with an atypical clinical presentation followed by a review of the literature.

Long-term Comparison of a Large Spot Vacuum Assisted Handpiece vs the Small Spot Size Traditional Handpiece of the 800 nm Diode Laser.

BACKGROUND The 800 nm long-pulsed diode laser machine is safe and effective for permanent hair reduction. Traditionally, most long-pulsed diode lasers used for hair removal had a relatively small spot size. Recently, a long-pulsed diode laser with a large spot size and vacuum assisted suction handpiece was introduced. The treatment parameters of each type of handpiece differ. Short and long-term clinical efficacy, treatment associated pain, and patient satisfaction are important factors to be considered. OBJECTIVE: This study aims to conduct a direct head to head comparison of both handpieces of the 800nm long-pulsed diode laser by evaluating long term hair reduction, treatment associated pain and patient satisfaction. METHODS: Thirteen subjects were enrolled in this prospective, self-controlled, single-center study of axillary laser hair removal. The study involved 4 treatments using a long pulsed diode laser with a large spot size HS handpiece (single pass), HS handpiece (double pass), and a small spot size ET handpiece according to a randomized choice. The treatment sessions were done at 4-8 week intervals with follow up visits taken at 6 and 12 months after the last treatment session. Hair clearance and thickness analysis were assessed using macro hair count photographs taken at baseline visit, at each treatment session visit and at follow up visits. Other factors including pain, treatment duration, and patients' preference were secondary study endpoints. RESULTS: At 6 months follow up visits after receiving four laser treatments, there was statistically significant hair clearance in the three treatment arms with 66.1 % mean percentage hair reduction with the ET handpiece, 43.6% with the HSS (single pass) and 64.1 % with the HSD (double). However, at one year follow up, the results significantly varied from the 6 months follow up. The mean percentage hair reduction was 57.8% with the ET handpiece treated axillas (n=9), 16.5% with the HSS (single pass) handpiece treated axillas (n=7), and 46.9% with the HSD (double pass) handpiece treated axillas (n=6). Thus, at one year follow up, there was a significant hair reduction that was similar in both the ET and HSD treated axillae (57.8% and 46.9 %), but only minimal hair reduction (16.5%)was observed in the HSS treated axillae. CONCLUSIONS: This is the first study that compared the long-term efficacy of the ET and HS handpieces after four treatment sessions with up to 12 months follow up after the last treatment session. It is also the first study that provided head to head comparison between HS (double pass), HS (single pass), and ET handpiece taking into consideration the end hair reduction result, the time consumed, the pain score experienced, and the overall patient satisfaction. HSD had better hair clearance and patient satisfaction when compared to ET and HSS. The long term follow up results showed that ET was superior to HSS (P less than .05), but was not superior to HSD (P greater than 0.05). However, HSD treated patients had lower pain scores with HSD than with ET. We conclude that ET handpiece is almost as efficacious as HSD handpiece, and the desired end results could be achieved with HDD with better patient satisfaction, less treatment duration and less pain.

J Drugs Dermatol. 2017;16(9):893-898.

Immediate skin responses to laser and light treatments: Therapeutic endpoints: How to obtain efficacy.

Clinical endpoints are immediate or early tissue reactions that occur during laser treatment. They can guide the laser surgeon in delivering safe and effective laser treatment. Some endpoints act as warning signs of injury to the skin; others can indicate a therapeutic response. The first article in this series reviewed undesirable and warning endpoints, and this article focuses on desirable and therapeutic endpoints and their underlying mechanisms in laser surgery. We will also review treatments without clinical endpoints.

Guidelines for the Topical Treatment of Psoriasis Vulgaris in the Levant and Iraq Area.

Psoriasis vulgaris is a common chronic, inflammatory, multisystem disorder that affects approximately 1.5% to 3.4% of the population in the Middle East. The disease has an impact on the quality of life in a significant number of affected patients. The majority of patients (approximately 70%) have mild to moderate psoriasis that is manageable with topical agents, which generally show a high efficacy to safety ratio. Topical agents can be used alone when treating patients with limited disease or may be used as adjunctive therapy for patients with more extensive psoriasis undergoing systemic treatment. Treatment should also be customized to meet individual patients' needs. To optimize the topical treatment of psoriasis in the Levant and Iraq area, dermatology experts from Iraq, Jordan, Lebanon, Palestine, and Syria met and initiated a project to develop guidelines and recommendations for the topical management of psoriasis. The guidelines are based on literature evidence and experts' opinions. We present recommendations for the use of topical corticosteroids, vitamin D analogues, calcineurin inhibitors, tazarotene, salicylic acid, anthralin, and coal tar, as well as combination therapy, based on their efficacy and safety profiles.

Combined 585 nm pulsed-dye and 1,064 nm Nd:YAG lasers for the treatment of basal cell carcinoma.

BACKGROUND AND OBJECTIVE: Basal cell carcinomas (BCCs) have supporting vasculature that serves as a target for vascular selective lasers. The objective of this study was to determine the effect of repeated treatment with a combined 585 nm pulsed dye laser (PDL) and 1,064 nm Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser on BCCs of superficial and nodular subtypes of varying diameters. STUDY DESIGN/MATERIALS AND METHODS: Ten subjects with 13 biopsy-proven BCCs received four combined PDL and Nd:YAG at treatments 2-4 week intervals. None of the BCCs met the criteria for Mohs micrographic surgery. The tumor and 4 mm of peripheral skin were treated using standardized parameters delivered with a 7 mm spot with 10% overlap. The treated area was excised and evaluated histologically for residual tumor. The primary study endpoint was histologic clearance of tumor. The secondary study endpoint was blinded investigator assessment of clinical endpoint and adverse effects. RESULTS: Approximately half of all tumors showed a complete response to four combined PDL and Nd:YAG treatments (n = 7/12, 58%). When stratified by size, 75% of all tumors <1 cm in diameter (n = 6/8) showed complete response. Tumor histologic types among the complete responders included superficial and nodular BCCs. All subjects with incompletely responding BCCs were on various forms of anticoagulation, which we hypothesize, may inhibit laser-mediated thrombosis necessary for the clinical effect. Blinded investigator assessment suggests that biopsy related erythema improves with subsequent laser treatments. CONCLUSIONS: Combined PDL and Nd:YAG laser is an effective means of reducing tumor burden in patients with BCC and may be a promising, emerging alternative therapy. Factors influencing treatment response includes the concomitant use of anticoagulation. Further studies are needed to investigate and optimize the utility of this treatment protocol.

Large area fractional laser treatment of mouse skin increases energy expenditure.

Fractional laser (FL) treatment is a common dermatologic procedure that generates arrays of microscopic treatment zones separated by intact tissue, promoting fast wound healing. Using a mouse model, we introduced a large area fractional laser treatment (LAFLT) method to study metabolic effects. Using two laser modalities, ablative FL (AFL) and non-ablative FL (NAFL), and exposing different percentages of mice's total body surface area (TBSA), we followed changes in metabolic parameters in real time using metabolic cages. Additionally, body composition, markers of inflammation, neurohormonal signaling, and browning of adipocytes were investigated. LAFLT, especially in high TBSA groups, had specific metabolic effects such as significantly increased average daily energy expenditure, increased fat mass loss, systemic browning of adipocytes, and inflammatory states, without compromising other organs. The ability of LAFLT to stimulate metabolism in a controlled way could develop into a promising therapeutic treatment to induce positive metabolic changes that replace or augment systemic drugs.

Acquired port-wine stains: A report of two cases and review of the literature.

BACKGROUND: Acquired port-wine stains (APWS) are rare vascular malformations that share the same clinical and histological features as their congenital counterparts. Rare cases of AWPS secondary to trauma or in association with medications have been reported in the literature. PATIENTS AND METHODS: We report two cases of APWS. One case appeared at the age of 2 months, the earliest reported in the literature and continued to evolve till the age of 3 years presenting with multifocal distribution mainly affecting the lower face. The second case developed during oral isotretinoin intake and persisted after discontinuation of the treatment. RESULTS AND CONCLUSIONS: The second patient declined treatment, but the first patient had a remarkable improvement following treatment with the pulsed dye laser, which remains the standard of care for capillary malformations on the face.

Dermatological manifestations associated with COVID-19 and COVID-19 vaccination: results from the Lebanese COVID registry.

BACKGROUND: A number of cutaneous manifestations and adverse cutaneous reactions have been associated with COVID-19 infection and vaccine. OBJECTIVES: A Lebanese national registry was established to characterize the dermatologic manifestations and adverse cutaneous reactions associated with COVID-19 infection and vaccination in a sample of the Lebanese population. METHODS: An observational cross-sectional study was conducted via a web-based clinical form distributed to physicians wishing to report their cases from May 2021 till May 2022. RESULTS: In total, 142 patients were entered in the registry, of which 133 were adults and nine were pediatric patients. The main dermatological manifestations reported with COVID-19 infection in the adult group were urticaria (32.9%), telogen effluvium (21.4%), morbilliform (10%), and papulosquamous (8.6%) eruptions. Urticaria was the most common adverse cutaneous reaction to the vaccine (33%). Interestingly, herpes zoster was triggered in 12 patients post vaccination in our series with this finding more frequently seen in patients above the age of 41 (P = 0.013). In the pediatric group, the most reported dermatological findings associated with COVID-19 infection were malar erythema (25%) and telogen effluvium (25%). One 16-year-old patient developed lichen planus after one dose of a COVID-19 vaccine. No deaths were reported in both age groups. CONCLUSION: This Lebanese registry adds more robust evidence that clinical manifestations of the COVID-19 virus and vaccine are diverse. More studies are necessary to establish the pathophysiology of these dermatological findings in the context of COVID-19 infection and vaccination.

Selective photothermolysis to target sebaceous glands: theoretical estimation of parameters and preliminary results using a free electron laser.

BACKGROUND AND OBJECTIVES: The success of permanent laser hair removal suggests that selective photothermolysis (SP) of sebaceous glands, another part of hair follicles, may also have merit. About 30% of sebum consists of fats with copious CH(2) bond content. SP was studied in vitro, using free electron laser (FEL) pulses at an infrared CH(2) vibrational absorption wavelength band. METHODS: Absorption spectra of natural and artificially prepared sebum were measured from 200 to 3,000 nm, to determine wavelengths potentially able to target sebaceous glands. The Jefferson National Accelerator superconducting FEL was used to measure photothermal excitation of aqueous gels, artificial sebum, pig skin, human scalp, and forehead skin (sebaceous sites). In vitro skin samples were exposed to FEL pulses from 1,620 to 1,720 nm, spot diameter 7-9.5 mm with exposure through a cold 4°C sapphire window in contact with the skin. Exposed and control tissue samples were stained using H&E, and nitroblue tetrazolium chloride staining (NBTC) was used to detect thermal denaturation. RESULTS: Natural and artificial sebum both had absorption peaks near 1,210, 1,728, 1,760, 2,306 and 2,346 nm. Laser-induced heating of artificial sebum was approximately twice that of water at 1,710 and 1,720 nm, and about 1.5× higher in human sebaceous glands than in water. Thermal camera imaging showed transient focal heating near sebaceous hair follicles. Histologically, skin samples exposed to ~1,700 nm, ~100-125 milliseconds pulses showed evidence of selective thermal damage to sebaceous glands. Sebaceous glands were positive for NBTC staining, without evidence of selective loss in samples exposed to the laser. Epidermis was undamaged in all samples. CONCLUSIONS: SP of sebaceous glands appears to be feasible. Potentially, optical pulses at ~1,720 or ~1,210 nm delivered with large beam diameter and appropriate skin cooling in approximately 0.1 seconds may provide an alternative treatment for acne.

Pulsed dye laser as a novel non-surgical treatment for basal cell carcinomas: response and follow up 12-21 months after treatment.

BACKGROUND AND OBJECTIVE: We showed previously that pulsed dye laser (PDL) is a potentially effective therapy for BCCs <15 mm on trunk and extremities. To follow-up, we conducted a study based on optimized parameters and expanded the duration of the study to at least 1 year after treatment. MATERIALS AND METHODS: Fourteen patients with 20 biopsy-proven BCCs on trunk and extremities, 8-35 mm in diameter, were treated. Each BCC received four consecutive PDL treatments at 3-4 week intervals. A 4 mm margin of clinically normal skin was also treated. Standardized photography was performed prior to each treatment and follow up visit. Patients were asked to consent for standard excision or at least scouting biopsies after treatment completion. RESULTS: Complete clinical response was seen with 19 of 20 treated BCCs, regardless of size and histologic subtype. One did not respond completely to therapy. All remaining 19 BCCs were followed between 12 and 21 months (median = 18 months) after the last PDL treatment. Of these 19 BCCs, only one recurred at 17 months follow up. The remaining 18 BCCs did not show any clinical signs of residual or recurrent tumor at 12-21 months follow-up. Overall, 90% (18/20 tumors) of treated BCCs in this study showed no clinical or histologic evidence of BCC more than 12 months after PDL treatment. Additionally, 18/19 (95%) BCCs less than or equal to 17 mm showed no evidence of residual or recurrent tumor clinically or on histology 12-21 months post-laser treatment. CONCLUSIONS: PDL treatment of BCC represents a novel, quick, and relatively non-painful treatment that does not usually produce scar and may represent an alternative treatment for certain types of BCC in the appropriate clinical setting. This study confirms prior findings regarding the efficacy of PDL in the treatment of BCC, with longer follow-up period.

755 nm alexandrite laser for the reduction of tumor burden in basal cell Nevus syndrome.

BACKGROUND AND OBJECTIVE: Basal Cell Nevus syndrome (BCNS) is characterized by numerous basal cell carcinomas (BCCs). Multiple treatments with the pulsed dye laser (PDL) have been shown, in small studies, to be effective for the treatment of superficial and nodular BCCs. Like PDL, the alexandrite laser can be vessel-selective, but has the added advantage of deeper tissue penetration. We evaluated the utility of the alexandrite laser in reducing the tumor burden in BCNS with a single treatment. STUDY DESIGN/MATERIALS AND METHODS: A case report and review of the literature are presented. A 45-year-old man with BCNS and a history of radiation therapy presented with an extraordinarily high tumor burden (>250 BCCs). As a compassionate measure to reduce the tumor burden, we investigated the utility of a single treatment of the long-pulsed 755 nm alexandrite laser to several BCC lesions. The treated lesions were evaluated at 2-month and 7-month clinical follow-up. Histopathologic analysis of a treated lesion was performed at 7-month clinical follow-up. RESULTS: At 2-month, and 7-month clinical follow-up, 15 of 18 treated lesions or about 83% of the alexandrite laser treated lesions showed a complete clinical response and appeared as hypopigmented areas with scarring. Histopathologic analysis of a treated lesion at 7-month clinical follow-up showed no evidence of residual tumor. CONCLUSIONS: The long-pulsed alexandrite laser may be helpful in significantly reducing tumor burden in difficult to manage BCNS patients with a single treatment. This provides a facile and practical treatment alternative for the management of challenging cases of BCNS. The limitation of this study is that it is a single case observation. Larger, prospective studies are needed to confirm these observations.

When not to treat cutaneous vascular lesions with the pulsed dye laser.

The availability of effective laser treatment for cutaneous vascular lesions has risen dramatically in recent years. At the same time, there has been a proliferation of laser providers with varying amounts of training-both medical and nonmedical. We report a series of four cases where patients presented for cosmetic evaluation of vascular lesions and were discovered to have more significant pathologic disease. In presenting these cases, we hope to illuminate a basic differential diagnosis that exists for cutaneous vascular lesions and remind healthcare providers that not all "cosmetic" concerns are benign in origin. There is a differential diagnosis that exists for cutaneous vascular lesions that is worth reviewing, and it should be considered in all patients presenting for laser treatment.

Intracutaneous ALA photodynamic therapy: dose-dependent targeting of skin structures.

BACKGROUND: Photodynamic therapy (PDT) using topical aminolevulinic acid (ALA) depends on local drug uptake, metabolism to porphyrins, and depth of light penetration using different wavelengths. Topical ALA-PDT has limited depth of drug penetration. We studied induced porphyrin distribution and PDT after intradermal ALA administration using different drug concentrations followed by high-fluence red light irradiation. MATERIALS AND METHODS: Intradermal injections (∼2 mm deep) of ALA concentrations from 0.0005% to 1% were studied in swine to evaluated porphyrin fluorescence before PDT and clinical and histological damage 24 hours after PDT. Porphyrin accumulation was measured by fluorescence microscopy of frozen section. PDT was performed 3 hours after intradermal injections using a 635 nm LED array at a fluence of 200 J/cm2 . Skin responses to PDT were observed grossly and by histology (blind evaluation). RESULTS: Intradermal ALA caused porphyrin accumulation in epidermis, hair follicles (HF), sebaceous glands (SG), sweat glands (eccrine glands, EG and apocrine glands, AG), and subcutaneous fat. Significant differences of fluorescence intensity were observed between different skin structures (P < 0.05), but there was no significant difference comparing HF to SG; epidermis with either HF or SG; and dermis with fat (P > 0.05). Intradermal ALA is potent. ALA concentrations ≥0.25% followed by red light exposures caused a very intense vascular PDT reaction. Moderate doses of injected ALA concentration (∼0.06%), selectively targeted EG. Low doses (≤0.016%) targeted fat; producing fat necrosis with minimal inflammation, manifested both clinically and histologically. In contrast to topical ALA-PDT, intradermal ALA-PDT can effectively photosensitize deep skin structures. CONCLUSION: Potentially, intradermal ALA-PDT using various ALA concentrations may be useful for treating vascular lesions (malformations, hemangiomas, tumors), EG/AG disorders, fat or deep targets in skin.

Late onset hypersensitivity reaction to hyaluronic acid dermal fillers manifesting as cutaneous and visceral angioedema.

INTRODUCTION: Hyaluronic acid fillers are gaining popularity all across the globe. Although this aesthetic treatment is considered relatively safe, or that most unwanted effects are related to technical faults of the injections or infections, hypersensitivity reactions are being reported in acute or delayed forms. We herein describe an unusual case of hypersensitivity reaction to hyaluronic acid dermal fillers of 12-month latency, manifesting as cutaneous and visceral angioedema, and refractory to steroids, antihistamines and omalizumab. AIM: We aim to raise awareness of delayed hypersensitivity reactions to hyaluronic acid fillers since patients often unaware due to the time lapse from the procedure. PATIENTS/METHOD: A 47-year-old female, presenting with cutaneous and visceral angioedema 12 months after uneventful injection of hyaluronic acid-based dermal fillers. RESULTS: Angioedema was refractory to systemic steroids, antihistamines and omalizumab. Symptoms resolved miraculously after dissolving the fillers with hyaluronidase. CONCLUSION: In almost all previously described cases of late-onset response to hyaluronic acid dermal fillers, swelling was restricted to the treated area, was responsive to steroids or required no intervention at all. To our knowledge, this is an unusual case of hypersensitivity reaction to hyaluronic acid dermal fillers of 12-month latency, manifesting as refractory cutaneous and visceral angioedema.

Safety and effectiveness of black tattoo clearance in a pig model after a single treatment with a novel 758 nm 500 picosecond laser: a pilot study.

BACKGROUND: Optimal selective photothermolysis of a pigment particle requires pulse durations equal to or less than the particle's thermal relaxation time (t(1/2)). Since tattoo particles in skin range in diameter from 40 to 300 nm, picosecond pulses would approximate t(1/2) more closely and, therefore, might be more effective at tattoo particle fragmentation. MATERIALS AND METHODS: India Ink (carbon) or iron oxide tattoos were placed on the back of a Yorkshire pig. Six weeks later, each tattoo was treated with either a 758 nm 500 picosecond laser (Cynosure), a 755 nm 30-50 nanoseconds laser, or left untreated. After 4 weeks, clinical responses were evaluated by three dermatologists based on pre- and post-treatment photographs; histopathologic findings were evaluated by a dermatopathologist; and electron microscopic findings were analyzed for treated and non-treated carbon tattoos. RESULTS: After a single treatment, picosecond-domain pulses at 758 nm produced a significantly greater degree of carbon tattoo clearance compared to nanosecond-domain pulses at 755 nm. For iron oxide tattoos, both modalities produced minimal-to-poor clearance that was generally comparable. Neither modality resulted in scarring, textural changes, or hypopigmentation, and there was no histopathologic evidence of scarring. Electron micrographs revealed the presence of amorphous material (treated pigment) in picosecond and nanosecond laser-treated tattoos, consistent with effective targeting of India Ink pigment. CONCLUSIONS: The 758 nm 500 picosecond laser is more effective at carbon tattoo clearance after one session in a porcine model than the 30-50 nanosecond laser emitting at a similar wavelength. Both lasers cleared carbon tattoos more effectively than iron oxide tattoos. Both lasers have a comparable safety profile, and neither produced clinical or histopathologic scarring. Further studies in humans are necessary to evaluate whether repeated treatments with picosecond versus nanosecond domain modalities might yield superior tattoo pigment clearance with a comparable safety profile.

Delineating melanoma using multimodal polarized light imaging.

BACKGROUND AND SIGNIFICANCE: Melanoma accounts for 3% of all skin cancers but causes 83% of skin cancer deaths. The first step in treatment of melanoma is the removal of the lesions, usually by surgical excision. Currently most lesions are removed without intraoperative margin control. Post-operative methods inspect 1-2% of the surgical margin and are prone to sampling errors. In this study we evaluate the use of reflectance and fluorescence polarization imaging for the demarcation of melanoma in thick fresh skin excisions. MATERIALS AND METHODS: Pigmented lesions clinically suspicious for melanoma were elliptically excised with proper margins. Elliptical surgical excisions were vertically bisected along the short axis of the specimen into two halves in the middle of the pigmented lesions. The vertically bisected tumor face was imaged. After that, one half of the sample was briefly stained in aqueous 2 mg/ml solution of tetracycline, whereas another half was stained in 0.2 mg/ml aqueous solution of methylene blue. Then both specimens were reimaged. Reflectance images were acquired in the spectral range between 390 and 750 nm. Fluorescence images of the tetracycline-stained tissue were excited at 390 nm and registered between 450 and 700 nm. Fluorescence of the methylene blue-stained samples was excited at 630 nm and registered between 650 and 750 nm. After imaging, the tissue was processed for standard H&E histopathology. The resulting histological and optical images were compared to each other. RESULTS AND CONCLUSIONS: Our findings demonstrate that both tetracycline and methylene blue are suitable for imaging dysplastic and benign nevi. Melanoma is better delineated in the samples stained in methylene blue. Accurate and rapid delineation of melanoma in standard fresh surgical excisions appears feasible.

The effect of 595 nm pulsed dye laser on superficial and nodular basal cell carcinomas.

BACKGROUND AND OBJECTIVE: Basal cell carcinomas (BCCs) have supporting vasculature that could serve as a target for 595 nm pulsed dye laser (PDL). The objective of this study was to determine the effect of repeated PDL treatments on BCCs of superficial and nodular subtypes and of varying diameters. STUDY DESIGN/MATERIALS AND METHODS: Twenty biopsy-proven BCCs received four 595 nm PDL treatments at 2-week intervals. The tumor and 4 mm of peripheral skin were treated using a set of previously optimized laser parameters: one pass, 15 J/cm2 energy, 3 ms pulse length, no cooling, and 7 mm spot size with 10% overlap. The treated area was excised and evaluated histologically for residual tumor. Histologic response rates of the PDL treated BCCs were compared with that of non-PDL treated, matched control tumors. RESULTS: Nearly all BCCs <1.5 cm in diameter (n = 12) showed complete response to four PDL treatments (91.7%; n = 11/12) versus 16.7% of controls (n = 2/12, P-value = 0.0003). BCCs > or =1.5 cm in diameter (n = 8) showed a complete response rate of 25% (n = 2/8) versus 0% of controls (n = 0/8, P-value = 0.2). Mean clinical tumor diameter of the complete responders was 1.1 cm (n = 13) versus 2.2 cm (n = 7) for incomplete responders (P-value = 0.005). Tumor histologic types among the complete responders included superficial, nodular, micronodular, and keratinizing. Incompletely responding BCCs showed a significant reduction in tumor burden after PDL treatment, with residual histologic tumor burden ranging from <1% to 29% of the original clinical tumor diameter, compared to 13-68% residual tumor burden for the corresponding controls (P-value = 0.05). CONCLUSIONS: PDL is an effective means of reducing tumor burden in patients with large BCCs and may be an alternative therapy in BCCs <1.5 cm in diameter.

Porphyrin distribution after topical aminolevulinic acid in a novel porcine model of sebaceous skin.

BACKGROUND AND OBJECTIVE: Aminolevulinic acid photodynamic therapy (ALA-PDT) depends on drug metabolism into porphyrins. Clinically, ALA-PDT has been used with a wide range of protocols for treating both epidermal and dermal targets, despite limited understanding of porphyrin biodistribution over time. We studied porphyrin accumulation after topical application of ALA in vivo, and also describe the porcine ear as a new animal model to study adnexal glands. STUDY DESIGN/MATERIALS AND METHODS: The microanatomy of anterior ear skin of swine was measured. Topical 20% ALA in water/ethanol was applied under occlusion. Biopsies taken after 5, 10, 15, and then every 15 minutes for a total of 3 hours were examined by fluorescence microscopy of frozen sections to assess accumulation and distribution of porphyrins. RESULTS: Porphyrin fluorescence of digital photomicrograph images was not visually apparent until 30-45 minutes after application, although quantitative pixel analysis showed a statistically significant increase in epidermal fluorescence only 15 minutes after ALA application. From 30 to 120 minutes, epidermis, hair follicles (HF), and sebaceous glands (SG) became progressively more fluorescent. Eccrine gland fluorescence began to be detected after 30 minutes; SG showed fluorescence starting at 45-75 minutes. Fluorescence in all sites reached maximum intensity from 75 to 180 minutes of incubation. There was a trend for HF and SG to express stronger fluorescence compared with epidermis and eccrine glands. CONCLUSION: Anterior pig ear skin is microanatomically similar to human sebaceous skin. The time-dependent accumulation of porphyrins in pilosebaceous units and eccrine glands in this model suggests other routes of uptake of topical ALA in addition to the trans-epidermal route. Apparently, time interval between ALA application and light exposure could be optimized for different uses of ALA-PDT.