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Granulomatous pigmented purpuric dermatosis (PPD) is a rare and poorly recognized histological variant of PPD, which commonly affects the distal extremities of mainly Far East Asian patients. Many of the reported cases are associated with hyperlipidemia or other associated systemic derangements. The authors hereby describe an additional case of granulomatous PPD affecting a 56-year-old Caucasian woman presenting unusually as a solitary lesion confined to the lower back. The report also describes dermoscopic findings, summarizes clinicopathological features of all the cases published till date, and discusses the histopathological differential diagnosis.

Background and Objectives: Since the development of laser-induced photothermolysis for the therapy of port wine stain (PWS) birthmarks, clinical results have shown that dark purple lesions usually respond well to the first three to five treatments. However, for most PWS, complete blanching is never achieved, and the lesion stabilizes at a red-pink color. The aim of this feasibility study is to demonstrate that with the aid of a local vacuum applied to the lesion site prior to laser exposure, photocoagulation of the smaller PWS blood vessels may be successfully achieved., Study Design/materials and Methods: Suction cups were designed to fit onto the hand pieces of commercial laser devices used for PWS laser therapy. One subject with normal skin and another with PWS skin were recruited for this study. Laser pulses of various fluences were applied at atmospheric pressure or shortly after (5-15 seconds) hypobaric pressures (17-51 kPa) were placed as test sites on the forearm of both subjects. The laser-induced purpura at the test sites was documented over the course of 1 week on both subjects and the resulting PWS blanching was optically quantified by visible reflectance spectrometry 7 months after therapy., Results: For the subject with normal skin, the laser fluence needed with hypobaric pressure (51 kPa) to induce similar purpura intensity to that observed with atmospheric pressure was approximately 35% lower. For PWS skin, all suction application times (5-15 seconds) and hypobaric pressures (17-51 kPa) resulted in more intense purpura and the PWS blanching 7 months after treatment was clinically significant for test sites treated with hypobaric pressures ranging from 17 to 34 kPa., Conclusions: The temporary and controlled dilation of the targeted blood vessels achieved with a local vacuum can significantly reduce the "small-vessel-limitation" in the treatment of PWS without increasing the risk of epidermal damage., ((c) 2005 Wiley-Liss, Inc.)

Background and Objectives: The average success rate in achieving total blanching of port wine stain (PWS) lesions treated with laser-induced selective photothermolysis is below 25%, even after multiple treatments. This is because smaller diameter (5-20 microm) PWS blood vessels are difficult to destroy with selective photothermolysis since the volumetric heat generated by absorption of laser light is insufficient to adequately heat the entire vessel wall. The aim of this study was to investigate a potential technique for more efficient photocoagulation of small diameter PWS blood vessels in PWS that respond poorly to selective photothermolysis., Study Design/materials and Methods: The blood volume fraction (BVF) in the upper dermis of the forearm of human volunteers was increased by placing an inflated blood pressure cuff on the upper arm. Applied pressures were in the range of 80-100 mm Hg for up to 5 minutes. The increased BVF was determined by matching reflectance spectra measured with that computed using a diffusion model. The impact of increased BVF on purpura formation induced by a 0.45 milliseconds pulsed dye laser (PDL) at 585 nm wavelength was investigated in normal and in PWS skin., Results: In the presence of a 100 mm Hg pressure cuff, the BVF, as determined from the diffusion model, increased by a factor of 3 in the forearm and by 6 in the hand. Increasing BVF by a factor of 3 corresponds to an increase in blood vessel diameters by a factor of radical 3 approximately 1.7. BVF increased at 1-3 minutes after application of the pressure cuff, remained constant at 3-5 minutes, and returned to baseline values at 3 minutes after removal of the pressure cuff. Approximately 40% less radiant exposure was needed to induce the same amount of purpura after PDL irradiation when the blood pressure cuff was used. Applying an 80 mm Hg pressure cuff reduced the required radiant exposure for purpura formation by 30%. Heating of blood vessels was calculated as a function of vessel diameter and of radiant exposure (at 585 nm and at 0.5 and 1.5 milliseconds pulse duration)., Conclusions: Enlarging the vessel lumen, for example, by obstructing venous return, can significantly reduce the "small-vessel-limitation" in PDL treatment of PWS. Dilation of PWS blood vessels enables a more efficient destruction of smaller vessels without increasing the probability of epidermal damage., (Copyright 2004 Wiley-Liss, Inc.)

For over 100 years many different methods have been used to determine capillary resistance as a measure of small vessel fragility. There is still no firm agreement as to the most suitable method; the procedure is not standardized and an objective system for measurement is lacking. We have developed a computerized system that makes it possible to count petechiae and determine their area without the results varying with different examiners. Although we tried to keep the conditions for our examinations constant, we found a wide individual spread. In spite of this, the capillary resistance of atopic subjects was significantly lower than that of healthy persons.