Leg ulcers

The treatment of leg ulcers is a common and sometimes difficult problem. They can be costly to treat and are associated with loss of working capacity and sometimes significant morbidity. In the western world, leg ulcers are most frequently caused by venous insufficiency, arterial insufficiency, neuropathy (usually diabetic), or a combination of these factors. The pathogenesis, clinical features, and management of these types of leg ulcers are emphasized in this review.

Necrobiosis lipoidica

Necrobiosis lipoidica has distinctive clinical and histopathologic features. Although theories abound, its cause and pathogenesis remain unknown. Despite many reports of effective treatments, a critical review of the literature suggests that none is uniformly effective.

Transfusion-associated graft-vs-host disease in patients with malignancies. Report of two cases and review of the literature

Graft-vs-host disease can develop in immunosuppressed individuals who receive blood-product transfusions that contain immunocompetent lymphocytes. We report two cases of fatal transfusion-associated graft-vs-host disease that developed in patients with Hodgkin's disease who were undergoing therapy. We review all cases of this entity in patients with malignancies, represented predominantly by patients with hematologic malignancies. The groups at risk for development of transfusion-associated graft-vs-host disease, the clinical presentation and course, and methods of diagnosis are summarized. Prevention of this highly fatal condition is possible by irradiation of blood products given to patients at risk, but problems remain in determining the groups that warrant such measures. Dermatologists need to have heightened awareness of this entity to facilitate more complete diagnosis and allow establishment of effective standards of care.

Treatment of tattoos by Q-switched ruby laser. A dose-response study

Tattoo treatment with Q-switched ruby laser pulses (694 nm, 40 to 80 nanoseconds) was studied by clinical assessment and light and electron microscopy. Fifty-seven blue-black tattoos or portions thereof (35 amateur and 22 professional) were irradiated with 1.5 to 8.0 J/cm2 at a mean interval of 3 weeks. Substantial lightening or total clearing occurred in 18 (78%) of 23 amateur tattoos and 3 (23%) of 13 professional tattoos in which the protocol was completed. Response was related to exposure dose. Scarring occurred in one case, and persistent confettilike hypopigmentation was frequent. Optimal fluence was 4 to 8 J/cm2. Clinicohistologic correlation was poor. Q-switched ruby laser pulses can provide an effective treatment for tattoos.

Serum albumin. Differences in assay specificity

Serum albumin is one of the most common parameters used in evaluating nutritional status. Three of the popular methods available for measuring serum albumin are serum protein electrophoresis and the two dye binding methods: BCG and BCP. BCG is currently the most popular method because of its simplicity, rapidity, and cost. Although electrophoretic methods are considered more accurate, BCP has shown to correlate well with electrophoresis in most cases. BCG often overestimates serum albumin levels, although its specificity can be improved by minimizing contact time with the serum sample. The average difference between BCG methods and other methods is usually 0.5-0.6 g/dL. From a quantitative standpoint, some might consider the difference in specificity of BCG versus the other two methods to be insignificant; however, from a qualitative standpoint, the difference could easily alter the interpretation of nutritional assessment parameters. Because of differences in analytical methods, serum albumin measurements should be interpreted in the context of the assay being used and the accepted normal range for that laboratory. Likewise, published studies, especially those that stratify degrees of malnutrition and/or risk of complications based on specific serum albumin levels, should specify the assay methodology utilized.

Selective photothermolysis of cutaneous pigmentation by Q-switched Nd: YAG laser pulses at 1064, 532, and 355 nm

Exposure of skin to nanosecond-domain laser pulses affects the pigmentary system by a process called selective photothermolysis, in which melanosomes and pigmented cells are preferentially altered. Due to the broad absorption spectrum of melanin, this effect may occur with wavelengths that penetrate to vastly different depths within tissue, potentially producing different biologic responses. The effects of single near-ultraviolet (355 nm), visible (532 nm), and near infrared (1064 nm) pulses of 10-12 nsec duration were determined in guinea pig skin using gross, histologic, and electron microscopic observations. Threshold response in pigmented skin was a transient immediate ash-white discoloration, requiring 0.11, 0.20, and 1.0 J/cm2, at 355, 532, and 1064 nm, respectively. At each wavelength, melanosomes were ruptured within keratinocytes and melanocytes, with cytoplasmic and nuclear alterations. Delayed epidermal depigmentation occurred, followed by gradual repigmentation. Deep follicular cells were altered only at 532 and 1064 nm, which produced permanent leukotrichia. The action spectrum for threshold response was consistent with mechanisms implied by selective photothermolysis. These data may be useful for consideration of treatment for cutaneous pigmentation abnormalities or unwanted follicular pigmentation, or both.

Are topical corticosteroids useful in phototherapy for psoriasis?

A prospective, randomized, double-blind, placebo-controlled trial was performed to assess the effect of a potent topical corticosteroid cream used in conjunction with ultraviolet B (UVB) phototherapy on psoriasis with respect to time to clearing and duration of remission after clearing. Of the 53 outpatients who received suberythemogenic UVB phototherapy three times per week, 24 applied the topical corticosteroid and 29 applied the placebo cream twice daily until clearing was achieved. Nine patients in each group failed to comply with the protocol. Although there was a trend toward a slightly more rapid response in the topical corticosteroid-treated group, there was no significant difference in patients' early response to therapy, number of treatments, and UVB dose required to achieve clearing. Patients in the topical corticosteroid-treated group remained in remission longer than did patients in the control group (183 vs 116 days). Life-table analysis predicts that 62% of emollient-treated patients flare within 6 months of clearing compared with only 42% of topical corticosteroid-treated patients (p less than 0.1). For most patients with psoriasis who receive UVB therapy in an outpatient setting, the use of potent topical corticosteroids appears to produce, at most, a modest beneficial effect.

Palisaded encapsulated neuromas. A clinicopathologic study

Reed et al described the clinical and light-microscopic findings of palisaded encapsulated neuromas in 1972, but few cases have been reported since. We have studied 81 consecutive tumors. Clinically, these were solitary, asymptomatic, 2- to 6-mm, flesh-colored papules, usually located on the face of middle-aged patients. The correct diagnosis was rarely made; the lesion was most often mistaken for a basal cell epithelioma, melanocytic nevus, or other benign tumor. Light microscopy revealed single or multiple encapsulated dermal lobules composed of interlacing Schwann cells. Variable numbers of fine axons and myelin sheath remnants were present. Palisading of nuclei was not a prominent feature. Electron microscopy demonstrated substantial numbers of class C fibers (mostly nonmyelinated) only partially enveloped by Schwann cell cytoplasm. Pathologically, palisaded encapsulated neuromas are distinctive true neuromas resembling those seen in the multiple mucosal neuroma syndrome. Electron-microscopic findings are similar to those seen in peripheral nerve regeneration, suggesting that palisaded encapsulated neuromas may be traumatic in origin, and could represent regeneration following local minor injury to the skin.

Cutaneous effects and therapeutic uses of heat with emphasis on infrared radiation

The adverse effects and therapeutic benefits of heat, specifically infrared radiation, on skin have received little attention. In this review we discuss the evidence indicating that heat and infrared radiation are not totally harmless, but that they may be involved in both photoaging and photocarcinogenesis. We also review the clinical syndrome thought to be caused by infrared radiation and the therapeutic uses of both local heat and infrared radiation.

Keratinocyte protein expression in rapidly regenerating epidermis following laser-induced thermal injury

We examined 20 punch biopsies taken from five patients at varying intervals following CO2 laser-induced thermal injury. The regenerating epidermis was studied with monoclonal antibodies AE1 and AE3 (directed against low and high molecular weight keratins), and involucrin, a protein found within the cellular envelope of the most mature keratinocytes. Twenty-four hours following thermal damage, there was extensive spillage of keratins and involucrin into the papillary dermis and disarray of all constituents of the necrotic keratinocytes. Early ingrowth of basaloid keratinocytes weakly expressed AE1. By 1 week, keratinocytes expressed AE1 in varying intensities throughout the epidermis. AE3 was present in its normal distribution, staining all but the most basaloid keratinocytes. Involucrin stained cells deep within the epidermis. Six weeks following the initial injury, the staining pattern within the epidermis had returned to normal. Thus, it appears that the regenerating epidermis produces low molecular weight keratins in cells at all levels and forms premature cellular envelopes, perhaps as a protective measure, before expression of these constituents reverts to the normal pattern. These findings suggest that keratinocyte differentiation in wound-healing following laser-induced thermal injury is similar to that seen in other types of injury. Observed clinical differences may be attributable to differences in keratinocyte proliferative or migratory capabilities.