The non-neuronal and nonmuscular effects of botulinum toxin: an opportunity for a deadly molecule to treat disease in the skin and beyond.

There is growing evidence that botulinum neurotoxins (BoNTs) exhibit biological effects on various human cell types with a host of associated clinical implications. This review aims to provide an update on the non-neuronal and nonmuscular effects of botulinum toxin. We critically analysed recent reports on the structure and function of cellular signalling systems subserving biological effects of BoNTs. The BoNT receptors and intracellular targets are not unique for neurotransmission. They have been found in both neuronal and non-neuronal cells, but there are differences in how BoNT binds to, and acts on, neuronal vs. non-neuronal cells. The non-neuronal cells that express one or more BoNT/A-binding proteins, and/or cleavage target synaptosomal-associated protein 25, include: epidermal keratinocytes; mesenchymal stem cells from subcutaneous adipose; nasal mucosal cells; urothelial cells; intestinal, prostate and alveolar epithelial cells; breast cell lines; neutrophils; and macrophages. Serotype BoNT/A can also elicit specific biological effects in dermal fibroblasts, sebocytes and vascular endothelial cells. Nontraditional applications of BoNT have been reported for the treatment of the following dermatological conditions: hyperhidrosis, Hailey-Hailey disease, Darier disease, inversed psoriasis, aquagenic palmoplantar keratoderma, pachyonychia congenita, multiple eccrine hydrocystomas, eccrine angiomatous hamartoma, eccrine sweat gland naevi, congenital eccrine naevus, Raynaud phenomenon and cutaneous leiomyomas. Experimental studies have demonstrated the ability of BoNT/A to protect skin flaps, facilitate wound healing, decrease thickness of hypertrophic scars, produce an anti-ageing effect, improve a mouse model of psoriasiform dermatitis, and have also revealed extracutaneous effects of BoNT arising from its anti-inflammatory and anticancer properties. BoNTs have a much wider range of applications than originally understood, and the individual cellular responses to the cholinergic impacts of BoNTs could provide fertile ground for future studies.

Electrosurgical facial resurfacing: a prospective multicenter study of efficacy and safety.

BACKGROUND: A novel electrosurgical technology that uses a bipolar electrode-tipped stylet to deliver relatively low-radiofrequency energy through an electrically conductive medium has been developed. OBJECTIVE: To evaluate the efficacy and safety of the radiofrequency resurfacing system for the treatment of facial wrinkles. DESIGN: Multicenter, prospective, noncomparative study with longitudinal follow-up. SETTING: Four US academic dermatologic surgery clinics. PATIENTS: Ninety-five patients with mild to severe photodamage (Fitzpatrick classes I-III) involving periorbital (75 treatment sites) and perioral (50 sites) facial skin. INTERVENTION: Radiofrequency resurfacing with the use of 2 to 3 passes at 125 or 139 V. MAIN OUTCOME MEASURES: Wrinkle and cosmetic improvements evaluated by patients, investigators, and, by means of photographs, an independent panel of 5 evaluators. RESULTS: All evaluators determined a positive mean improvement in wrinkles for both periorbital and perioral anatomic sites, with greater improvement for patients with more severe wrinkles at baseline. An increased number of passes and higher voltage settings had a positive impact on wrinkle improvement. Transient postinflammatory hyperpigmentation occurred in 26% of periorbital and 4% of perioral sites. Hypertrophic scars occurred in 3.8% of treatment sites, with all but 1 scar resolving by 6 months. For the most part, healing was rapid, pain was minimal, and erythema largely resolved within 2 months. Other untoward effects were relatively few and short-lived. CONCLUSIONS: At the study settings used, radiofrequency resurfacing is an effective modality in the treatment of periorbital and perioral wrinkles in patients with Fitzpatrick class I, II, and III photodamage. There is less severe postoperative morbidity than seen with carbon dioxide or coagulating erbium:YAG lasers. The potential risks are similar to those seen with other resurfacing modalities.

Modulating the Er:YAG laser.

BACKGROUND AND OBJECTIVES: In the past 2 years, there has been some controversy about the optimal laser system, or combination of systems, for cutaneous resurfacing. Initially, it seemed that the Er:YAG laser would have significant advantages over the CO(2) laser. In practice, some of those who jumped early onto the Er:YAG bandwagon have been unimpressed with the degree of skin tightening that can be achieved with this system. Also, the excessive bleeding induced by the Er:YAG lasers prevented deeper vaporization. During the past 18 months, three new "modulated" Er:YAG lasers have been produced that are said to be able to achieve CO(2) laser-like effects, while maintaining the Er:YAG laser advantages. The purpose of this article is to examine these new systems and to discuss their potential benefits, if any, over the "conventional" Er:YAG lasers, and the CO(2) lasers. STUDY DESIGN/MATERIALS AND METHODS: The author has collected data from his own experience and that of his colleagues in the department of dermatology at University of California at San Francisco. The author has used all three types of modulated Er:YAG laser on patients presenting for cosmetic laser resurfacing and the treatment of many benign conditions over an 18-month period. RESULTS: All three modulated forms of Er:YAG lasers have been demonstrated to provide better coagulation than the conventional Er:YAG lasers. The Derma-K and the Contour Er:YAG lasers were able to induce tissue contraction/desiccation similar to the CO(2) laser. The author and his colleagues have induced only two cases of permanent hypopigmentation in over 50 cases during the past 18 months while using the Er:YAG laser, significantly less than might be expected with the CO(2) lasers. CONCLUSIONS: If a laser surgeon is happy with the results obtained with a high-energy, short-pulse CO(2) laser, then there seems little reason to consider changing to an Er:YAG laser. The modulated Er:YAG lasers have definite advantages over the conventional Er:YAG lasers. They exhibit better control of hemostasis and can ablate tissue to a greater depth than the conventional Er:YAG lasers. The Er:YAG lasers might induce less permanent hypopigmentation than the CO(2) lasers.

Management of cutaneous verruciform xanthoma.

Verruciform xanthoma is an uncommon mucocutaneous condition of uncertain cause that only occasionally affects the skin. The histopathology is distinctive for the presence of foamy histiocytes present within elongated dermal papillae. Although simple excision of intraoral lesions is reportedly curative, treatment of cutaneous lesions has not been previously reported. We describe a 62-year-old man with a large lesion of verruciform xanthoma affecting both inguinal folds. Immunohistochemical staining, reverse transcriptase polymerase chain reaction for human papilloma virus, and ultrastructural analysis were performed to investigate the pathogenesis of this lesion. The results of these studies support the theory that the source of lipid in dermal histiocytes is degenerating keratinocytes. Initial treatment with wire loop electrosection, pulsed dye (585 nm) laser, and x-ray therapy of this patient proved unsuccessful. Preliminary success has been achieved using wide surgical excision with primary closure.

New facial rejuvenation techniques.

The popularity of cutaneous laser resurfacing has soared in recent years. For optimal clinical improvement, patients have been limited to the carbon dioxide and erbium:yttrium aluminum garnet lasers. With these systems, tissue can effectively be ablated to induce collagen shrinkage and remodeling that result in an improved clinical appearance. The prolonged recovery periods associated with traditional cutaneous laser resurfacing have sparked an immense interest in devices that rejuvenate the skin while minimizing adverse effects. Both physicians and patients seem willing to accept more gradual improvement if it is associated with fewer complications such as prolonged erythema or delayed-onset hypopigmentation. The following review discusses the newest devices in development or currently available for skin rejuvenation.

Recalcitrant scarring follicular disorders treated by laser-assisted hair removal: a preliminary report.

BACKGROUND: Recalcitrant scarring follicular disorders have been treated previously by removing hair follicles both surgically by scalp resection with skin grafting and with X-ray epilation. Laser-assisted hair removal may provide an alternate method of hair removal with less associated morbidity. OBJECTIVE: The goal is to determine whether laser-assisted hair removal can be used to treat follicular inflammatory disorders by destroying hair follicles. METHODS: Three patients with various scarring follicular disorders (dissecting cellulitis of the scalp, keratosis pilaris spinulosa decalvans, and pseudofolliculitis barbae) were treated with the long-pulse non-Q-switched ruby laser and followed clinically. RESULTS: The patients tolerated the treatments well without significant side effects and noted improvement of their condition along with decreased hair growth in the treated area. CONCLUSION: Laser-assisted hair removal may provide a safe, effective means of treating recalcitrant follicular disorders.

Ultrastructure of collagen thermally denatured by microsecond domain pulsed carbon dioxide laser.

BACKGROUND: Clinical improvement in photodamaged skin after carbon dioxide (CO2) laser resurfacing is thought to result in part from thermal collagen shrinkage. The presence of such collagen has not been unequivocally demonstrated. To identify and characterize the morphological features of collagen after CO2 laser exposure, we irradiated ex vivo human facial skin and bovine calcaneus tendon with microsecond domain pulsed CO2 laser energy and examined specimens for histopathological and ultrastructural changes in collagen. OBSERVATIONS: In dermis and tendon, 3 zones of collagen structure were apparent on electron microscopy. The first, most superficial zone demonstrated loss of collagen structure. The second zone consisted of admixed normal collagen fibers and thickened collagen fibers. Zone 3 consisted of normal-appearing collagen fibers. CONCLUSIONS: Ultrastructural examination of irradiated collagen revealed distinct morphological zones of denatured collagen fibers. Partially denatured fibers had an increased diameter consistent with lineal shrinkage. Zonal distinction was undetectable by light microscopy. Ultrastructurally, the zones of denatured collagen located above the normal fibers correlated with the zone of altered material seen on light microscopy. These findings suggest that collagen fiber shrinkage does occur after pulsed CO2 laser irradiation and that this phenomenon contributed, at least in part, to the immediate tissue contraction observed clinically.

Scalp metastases mimicking alopecia areata. First case report of placental site trophoblastic tumor presenting as cutaneous metastasis.

BACKGROUND: Placental site trophoblastic tumor (PSTT) is a rare neoplasm of intermediate trophoblastic cells of the placenta. There is a wide range of biologic behavior, with metastases occurring in about 15% of cases. Cases with metastases have all presented with abnormal vaginal bleeding or gynecological symptoms. METHODS: We describe a 31-year-old G3P3003 woman who presented with several alopecic patches resembling alopecia areata, which on biopsy proved to be metastatic, previously unsuspected, PSTT. CONCLUSIONS: This represents the first case in which PSTT presented initially with metastases, and specifically, with cutaneous metastases. A new primary tumor source of alopecia neoplastica is presented. The role of mitotic counts in predicting prognosis in PSTT is supported. Alopecia areata was mimicked very closely. Dermatologists should be alert to any features atypical of alopecia areata, including erythema, induration, or palpability, and maintain a low threshold for biopsy in atypical cases.

Anti-human epithelial antigen (Ber-EP4) helps define basal cell carcinoma masked by inflammation.

BACKGROUND: Anti-human epithelial antigen (Dako-Ber-EP4) is an antibody raised in mice that reacts with two glycoproteins of 34 and 49 kD. These glycoproteins are present on the cell surface and in the cytoplasm of basal cell carcinoma (BCC) cells, sweat glands, and some hair follicles in the skin. METHODS: We selected 27 BCCs (15 nodular, 11 morpheic/infiltrative, and one adenoid) and one trichoblastoma and performed rapid immunohistochemical studies with Ber-EP4 and a labeled streptavidin biotin alkaline phosphatase system. RESULTS: Twenty-seven of 27 BCCs and one of one trichoblastoma were positive for Ber-EP4. Thirteen of 27 BCCs stained with Ber-EP4 showed areas of BCC in dense inflammation that were better defined by the Ber-EP4 immunostain than by the H&E stain. In two cases persistent infiltrative BCC was found in the final Mohs margins while appearing negative with routine H&E. Several instances occurred where negative Ber-EP4 in inflammatory fields resulted in tissue sparing with the avoidance of a further Mohs (insurance) layer. CONCLUSION: In conclusion, we found mouse anti-human Ber-EP4 a useful and reliable marker for BCC. This antibody helps to locate latent BCC tumor in inflammatory Mohs margins.

Nodular basal cell carcinoma in vivo vs in vitro. Establishment of pure cell cultures, cytomorphologic characteristics, ultrastructure, immunophenotype, biosynthetic activities, and generation of antisera.

BACKGROUND AND DESIGN: In this study we developed an in vitro model of nodular basal cell carcinoma (BCC). We obtained pure cultures of BCC cells and compared the morphologic characteristics, ultrastructure, immunophenotype, and behavior of cultured tumor cells with those of their in vivo counterparts. Tumors were excised from patients undergoing Mohs micrographic surgery. We established 69 primary cell cultures from 32 patients with nodular BCC. RESULTS: Three cell types grew in primary cultures: fibroblasts, normal-appearing keratinocytes, and cells with dual (spindle and epithelioid) morphologic characteristics. Contaminating fibroblasts were removed using 0.125% trypsin-0.02% edetic acid, and normal-appearing keratinocytes were cornified and eliminated by temporarily increasing the concentration of calcium in the growth medium. The cells with dual morphologic characteristics remained intact and exhibited relentless growth in pure cultures. That these seemingly immortal cell strains represent true nodular BCC was demonstrated by (1) their biphasic morphologic characteristics and very slow cell growth rate, (2) their capability for anchorage-independent growth in soft agar, (3) their ultrastructural similarities to freshly excised nodular BCC, (4) their ability to generate antibodies selectively labeling nodular BCC tumor nests in vivo, and (5) their immunophenotypic similarities to BCC in vivo on more than 20 different cell markers. CONCLUSIONS: This study provides a simple technique for establishing pure cell cultures of nodular BCC and describes extensively the in vitro parameters of tumor cell growth. The striking differences in behavior of cultured tumor cells in the presence or absence of normal-appearing keratinocytes suggest that normal human epidermal keratinocytes can suppress the growth of BCC cells.

The efficacy of various degreasing agents used in trichloroacetic acid peels.

BACKGROUND: Adequate preparation of the skin is necessary for a successful chemical peel. Little detailed attention has been given to the effect of degreasing on the efficacy of the peel. OBJECTIVE: To assess the influence of degreasers on the peel, compare their flammabilities, and discuss alternatives. METHODS: Six patients with androgenetic alopecia and widespread actinic keratoses of the scalp were treated with 35% trichloroacetic acid. Scalps were divided into sections and degreased with acetone, rubbing alcohol, Freon Skin Degreaser, or Hibiclens. The influence of these degreasers on trichloroacetic acid peels was assessed by clinical and histologic examination. CONCLUSION: Acetone was not found to be superior to the other agents. Furthermore, the flashpoint of acetone is markedly lower than the others, making it more flammable and hazardous in the workplace. The use of alternative degreasers may lessen or eliminate this hazard.

A reevaluation of the effect of occlusion on the trichloroacetic acid peel.

BACKGROUND: Prior studies have demonstrated reduced wounding with trichloracetic acid (TCA) peels after tape occlusion. It is therefore reasonable to question whether or not other types of occlusion may have similar effects, particularly those used in routine postoperative care. OBJECTIVE: To reevaluate the effect of occlusion after TCA peels in multiple human models using various forms of dressings, at various times postoperatively, and to make recommendations regarding wound care that will not adversely affect the efficacy of the peel. METHODS: Equal-sized sections of anterior alopecic scalps of four patients were peeled with 50% TCA, occluded with bacitracin, Vigilon, or Tegaderm at various times postoperatively, and biopsied 1 day later. Depths of necrosis were measured and compared with nonoccluded controls. RESULTS: Bacitracin ointment and Vigilon did not lessen TCA wounding, and sometimes actually enhanced it. Conversely, Tegaderm lessened the degree of the TCA wound. Timing of application played a role in the case of occlusion with Vigilon. CONCLUSION: Occlusives used in conjunction with TCA peels do not have a uniform effect on depth of necrosis. Ointments and Vigilon can be used without reducing the efficacy of the TCA peel. Multiple subjects and rigid control of variables are necessary in studies of TCA-induced necrosis.

Rapid cytokeratin stains enhance the sensitivity of Mohs micrographic surgery for squamous cell carcinoma.

BACKGROUND: Recurrence of squamous cell carcinoma (SCC) following Mohs micrographic surgery is uncommon. However, such cases do exist, presumably because of incomplete excision. Identification of single cells or small clumps of SCC tumor may be extremely difficult and can be compromised by inflammatory reaction. OBJECTIVE: The purpose of this study was to evaluate the benefits of incorporating rapid cytokeratin (CK) stains into Mohs technique. METHODS: Simple modification of standard immunoenzyme techniques allows keratin-specific staining to be achieved in less than 90 minutes on Mohs cryostat sections. We used the rapid labeled streptavidin biotin anticytokeratin method at the stage when no tumor was apparent by hematoxylin and eosin staining in 20 patients with large, aggressive, or recurrent invasive SCCs. RESULTS: In eight cases, single cells or small clumps of SCC tumor were identified utilizing AE-1 monoclonal antibody. These patients subsequently underwent further surgery, including wider tumor resection, superficial parotidectomy, or postoperative radiation therapy. CONCLUSION: The rapid CK antibody staining technique enhances the sensitivity of tumor identification in Mohs micrographic surgery, and should reduce tumor recurrence rates.

Rapid staining with carcinoembryonic antigen aids limited excision of extramammary Paget's disease treated by Mohs surgery.

Extensive extramammary Paget's (EMPD) disease of the perineum in a 68-year-old man was treated by Mohs surgery. To facilitate identification of involved tissue a rapid staining carcinoembryonic antigen was used. This technique proved a useful adjunct to conventional hemotoxylin-eosin (H&E) stains. It was especially useful in highlighting involvement in areas of marked dysplasia/artifact where discrimination is often difficult. It is recommended that such a technique offers considerable benefits over H&E staining when confronted by such tissue morphology.

Pseudocyst of the ear. Surgical treatment.

BACKGROUND: Pseudocyst of the auricle is characterized by an asymptomatic swelling caused by an intra-cartilaginous accumulation of fluid. Treatments include aspiration, steroid injection, and surgical intervention. OBJECTIVE: To present two cases of pseudocyst of the auricle treated surgically with an open, deroofing technique. METHODS: Two cases are presented and the relevant literature is reviewed. CONCLUSION: Optimal treatment for pseudocyst of the ear involves removal of the anterior cartilaginous leaflet of the pseudocyst with repositioning of the overlying flap of skin. This results in a normal-appearing auricle with minimal scarring or recurrence of the pseudocyst.

Direct transfer of curettings to cryostat chuck in Mohs micrographic surgery.

In the routine handling of Mohs specimens the curetted first layer is integral to the process of tumor identification. Small specimens may be smeared inadvertently on filter paper or gauze or even lost between the operating room and laboratory. An efficient method for processing small curetted specimens has been devised that bypasses the use of a tissue tray. This method improves tissue morphology and saves time.

Local anesthetic allergy. Its recognition and avoidance.

Local anesthetics are perhaps the most important drugs used in dermatologic surgery. They allow a variety of procedures to be performed safely and comfortably. Although generally well-tolerated, patients frequently report adverse reactions to these agents and may be labeled as "caine sensitive". In this review we will discuss the approach to the patient with possible local anesthetic sensitivity and in particular will focus on the role of skin testing and challenge in evaluating these patients.

Benign lymphangioendothelioma.

We have studied eight cases of an acquired lymphatic endothelial lesion for which we propose the name "benign lymphangioendothelioma." The lesions developed as solitary, slowly extending, erythematous macules and plaques, usually occurring on the extremities or the shoulders in adolescents or adults. The characteristic histopathologic feature is permeation of the dermal collagen by flattened, endothelium-lined channels and spaces. Hemorrhage, iron deposition, and inflammation were not part of the lesion. Ulex europaeus agglutinin I labeled the lesional endothelial cells consistently, but factor VIII-related antigen labeling was negative. This histologic pattern and the special studies suggested a lymphatic lesion. Surgical excision, performed in six patients, was not followed by recurrence.