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Notes: Epidermolysis bullosa acquisita (EBA) is an autoimmune bullous disease with frequent ocular involvement, but visual loss is rare. In contrast, EBA patients with predominant IgA autoantibodies more frequently develop severe ocular involvement, which tends to be refractory to therapy. We report two patients with ‘IgA–EBA’ with ocular involvement. Both initially presented with a generalized bullous disease, and direct immunofluorescence microscopy demonstrated IgA in the basement membrane zone of the skin, and in the conjunctiva and cornea of patient 1. On salt-split patient skin, IgA was found predominantly on the dermal side of the artificial split in both patients. Direct immunoelectron microscopy demonstrated IgA below the lamina densa in close association with the anchoring fibrils in both patients. In patient 1, who had a prolonged course of the disease, the skin disorder responded well to treatment with cyclosporin, but the ocular involvement ended in bilateral blindness despite repeated surgical treatment. In patient 2, the blister formation and scarring conjunctivitis was stopped by a combination of prednisolone and colchicine. These patients show that in subepithelial blistering diseases, early delineation of disease nosology is critical to detect subtypes with severe ocular involvement such as ‘IgA–EBA’. In addition, colchicine may be a valuable alternative in the treatment of EBA with ocular involvement.

Notes: A high incidence of severe pruritus had been observed after the administration of hydroxyethyl starch (HES) on account of plasma volume substitution and improvement of the microcirculation. The aim of this study was to elucidate the possible pathomechanisms of HES-induced itching. Sking biopsies were taken from 93 patients, half of them presenting with pruritus, who received HES of various preparations and cumulative dosages. The samples were subjected to immunoelectron microscopical investigation using an antibody highly specific for HES. After infusioin therapy with HES, formation of intracytoplasmic storage vacuoles in the skin could be demonstrated in all patients. A dose- dependent uptake of HES was first detectable in macrophages and, thereafter, in endothelial and epithelial cells. Consecutive control biopsies taken from single patients revealed a subsequent reduction of the vacuoles, in size and number, within 3 years, thus indicating a regular cutaneous metabolism of HES. Patients suffering from pruritus consistently showed additional deposition of HES in small peripheral nerves. HES-reactive vacuoles could be demonstrated in the Schwann cells of unmyelinated, as well as small myelinated, nerve fibres, and in endoneural and perineural cells. Neural devacuolization paralleled the clinical improvement in the symptoms. In conclusion, HES deposits in cutaneous nerves, as a consequence of a higher cumulative dosage, may account for the itching seen after HES infusion.

Notes: Subcutaneous swellings uncommonly occur at vaccination or desensitization injection sites and may present long after the procedure. Such lesions can show a range of histopathological appearances that are not well recognized, often leading to erroneous diagnoses. We describe the clinicopathological features of 13 cases (12 adults, 1 child) with subcutaneous swellings presenting at injection sites (upper arm n12, thigh n1). In the cases studied the histological appearances were varied, although predominantly the subcutis was involved. Six cases showed a mixed panniculitis with focal fat necrosis and fibrosis. Four cases demonstrated a pseudolymphomatous pattern, mimicking a B cell lymphoma. One case was reminiscent of lupus profundus and 3 other cases resembled deep granuloma annulare. Importantly, all cases contained histiocytes with violaceous granular cytoplasm, representing ingested aluminium salts employed for adsorption of antigens in the injection preparations. Energy dispersive x-ray microanalysis in 8 cases confirmed a positive aluminium peak. Electron microscopy in 3 cases showed crystalline material in the histiocytes. In conclusion, the spectrum of histological appearances in so called aluminium granuloma can be misleading and it is important to identify the characteristic histiocytes of this condition, for otherwise erroneous diagnoses, with serious clinical implications, can follow.

Notes: Axillary granular parakeratosis is a recently described condition presenting with erythematous hyperkeratouc papules and plaques. We report on nine women and one man with eruptions not only localized to the axillae. Biopsy specimens were investigated by histology, immunohistochemistry, electron microscopy, immuno-electron microscopy, and in situ hybridization. In general, the epidermis was hyperplastic and showed a well preserved stratum granulosum. In the upper dermis a discrete perivascular CD4+ T-cell infiltrate was found, CD1 + dendritic cells were absent from the epidermis. The distribution pattern of the epidermal keratins (keratin 5/14, 1/10) and the expression of involucrin was regular. The horny layer was excessively thickened and parakeratotic. The nuclear remnants showed marginal chromatin condensation and were reactive for the nick-end labeling technique using TdT-mediated dUTP-biotin. The eorneocytes were characteristically replete with basophilic granules which showed both ultrastructural features of keratohyalin granules and immunoreactivity for filaggrin. Loricrin was expressed irregularly in small L-granules. Granular parakeratotic cells revealed regular development of a cornified envelope while cell membranes and desmosomes remained undegraded. In conclusion, our studies on granular parakeratosis suggest a basic defect in processing of profilaggrin to filaggrin that results in a failure to degrade keratohyalin granules and to aggregate keratin filaments during cornification. Associated abnormalities of the cell surface structures and dysregulation of cornified envelope components may account for the retention hyperkeratosis. Further studies are necessary to clarify the etiology of this unique, acquired disorder of keratinization that localizes to intertriginous areas and body folds.

Notes: Glycoproteins of the carcinoembryonic antigen family (CEA) and epithelial membrane antigen (EMA) are established markers for glandular and mucosal tissues. However, their precise ultrastructural distribution in sweat glands has not been determined as yet. Therefore, normal human skin, 19 cases of various sweat gland neoplasms, Paget's disease, and cutaneous metastases of visceral carcinomas were stained with well-defined antibodies using a postembedding immunogold technique. In some cases, a new method of re-embedding paraffin material for immunoelectron microscopy was applied. In normal sweat glands, immunoreactivity of the endoplasmic reticulum and vesicles indicated biosynthesis and processing of CEA and EMA. Along the luminal surfaces both CEA and EMA represented an integral part of microvilli. However, a differential expression of CEA and EMA was demonstrated in apocrine epithelia, mucous cells of eccrine glands, and sweat ducts. In fetal glands, CEA was associated with formation of secretory and ductal lumina. The overall cellular distribution of CEA and EMA was highly preserved in benign sweat gland neoplasms whereas malignant neoplasms were characterized by loss of protein targeting and cellular polarity. In conclusion, these immunoelectron microscopical findings suggest a role of CEA and EMA for cell differentiation and secretory mechanisms of sweat gland epithelia.

Notes: The vanilloid receptor subtype 1 (VR1/TRPV1) is a non-selective cation channel that binds the vanilloid capsaicin and endogenous cannabinoids. In human skin, VR1 has recently been shown to be expressed by keratinocytes in vitro and in vivo. To determine a precise localization of VR1 in other cutaneous compartments in particular cutaneous nerve fibres, we investigated VR1 immunoreactivity as well as mRNA and protein expression in a series of normal and capsaicin-treated human skin. VR1 immunoreactivity could be observed in cutaneous sensory nerve fibres, mast cells, epidermal keratinocytes, dermal blood vessels, the inner root sheet and infundibulum of hair follicles, differentiated sebocytes, sweat gland ducts and the secretory portion of eccrine sweat glands. Upon RT-PCR and Western blot, the expression of VR1 was confirmed in primary mast cells and keratinocytes from human skin. During capsaicin therapy, VR1-receptor distribution was unchanged, while a reduction of neuropeptides (substance P, calcitonin gene-related peptide) was observed in nerve fibres. After cessation of capsaicin therapy, neuropeptides re-accumulated in skin nerves. In conclusion, VR1 is widely distributed in the skin, suggesting a central role for this receptor, e.g. in nociception and inflammation.

Notes: Contact dermatitis (CD) is a frequent dermatological disease with a high socioeconomical impact characterized by acute to chronic inflammation of the skin, often leading to therapy-resistent eczema. Proteinase-activated receptor-2 (PAR-2), a G-protein-coupled receptor for certain serine proteases, is localized on keratinocytes, endothelial cells, and nerve fibers and has been demonstrated to play a role during inflammation of several tissues. However, the precise role of PAR-2 and the underlying mechanism of PAR-2-induced regulation of inflammation are still fragmentary. Therefore, we were interested in whether or not PAR-2 is involved in cutaneous inflammation using a model of experimentally induced allergic (ACD) and irritant (ICD) contact dermatitis. In wild-type (PAR-2+/+) mice, PAR-2 agonists induced an increased intradermal edema and enhanced plasma extravasation with a maximum between 3 and 24 h. These inflammatory responses were significantly diminished in PAR-2-deficient (PAR2–/–) mice and controls (vehicle). Morphological analysis revealed a dramatic increase of spongiosis and intradermal edema along with enhanced infiltration of neutrophils and monocytes in PAR-2+/+ mice as compared with PAR-2–/– mice. Interestingly, nitric oxide (NOS) inhibitors significantly diminished these effects, indicating a role of NO in PAR-2-induced inflammatory responses of the skin. Functional studies at the RNA and protein level further revealed PAR-2-induced upregulation of the cell adhesion molecules ICAM-1 and E-selectin by dermal microvascular endothelial cells during inflammation, suggesting that PAR-2 directly regulates cell adhesion molecule function during skin inflammation. PAR-2 agonists also stimulated upregulation of mediators involved in cutaneous inflammatory responses such as IL-6 and NO in murine and human (dermal) endothelial cells. Together, these results strongly suggest a proinflammatory role of PAR-2 during CD and probably other inflammatory dermatoses, especially during the early phase characterized by edema, plasma extravasation, and recruitment of inflammatory cells to the site of inflammation. Thus, PAR-2 antagonists may be therapeutic tools for the treatment of inflammatory skin disorders such as contact dermatitis and atopic eczema.

Notes: The presence of immunoglobulin A (IgA) and secretory component (SC) was investigated in normal human skin and in cutaneous neoplasms including a variety of sweat gland tumors. Immunohistochemistry in normal sweat glands revealed the occurrence of secretory IgA (sIgA) as indicated by reactivity for IgA and SC in serial sections. The majority of 28 cases of sweat gland tumors could be demonstrated to retain their ability to produce IgA and SC. In normal as well as in neoplastic sweat glands heaviest staining for sIgA could be found in the lumina and at the surface of lining epithelia. This is comparable with the presence of sIgA in breast or intestinal neoplasms. In contrast other epidermal cysts or solid tumors were not labelled. In view of recent immunohistochemical studies the demonstration of IgA and SC may be of differentiating value in cutaneous glandular neoplasms.

Notes: The proopiomelanocortin (POMC) products α-melanocyte stimulating hormone (α-MSH) and adrenocorticotropin (ACTH) bind to specific receptors known as the melanocortin (MC) receptors. There is increasing evidence that the MC receptor subtype 1 (MC-1R) is expressed in vitro by several other cutaneous cell types besides melanocytes and keratinocytes. Our knowledge on the MC-1R expression in skin, however, remains fragmentary. In order to examine the expression of MC-1R in human skin cells in vitro and in situ, we made use of a recently described antibody directed against the amino acids 2-18 of the human MC-1R. Flow cytometry analysis revealed the highest MC-1R antigenicity in normal melanocytes and keratinocytes, followed by dermal fibroblasts, microvacualar endothelial cells and WM 35 melanoma cells. Little or no expression was detected in KB carcinoma cells and Fs4 fibroblasts. In normal human skin, immunoreactivity for the anti-MC-1R antibody was detected in hair follicle epithelia, sebocytes, secretory and ductal epithelia of weat glands, and periadnexal mesenchymal cells. Interfollicular epidermis was largely unreactive in adult skin as opposed to undifferentiated kertinocytes of fetal skin. Our findings form a framework within which MC-1 receptor expression can be studied in various skin diseases.

Notes: Ultraviolet (UV) light is one of the most crucial environmental factors with regard to its capacity to induce skin cancer, premature aging of the skin, and immunosuppression. Although UV directly affects the function of epidermal cells, many of these effects are mediated by the induction of cytokines, growth factors, and neuropeptides such as α-melanocyte-stimulating hormone (α-MSH). Recently, in addition to its well-known pigmentation inducing activity, a strong anti-inflammatory as well as an immunomodulatory potential of α-MSH has been recognized. The aim of this study was to determine whether UV irradiation affects the expression of both α-MSH and the melanocortin-1 receptor (MC-1R) in human epidermis in vivo. The volar aspects of the forearms were exposed to twice the minimal erythema dose of solar simulating radiation (SSR). Three, 6, and 24 h after irradiation, the pro-opiomelanocortin (POMC) and interleukin-10 (IL-10) mRNA levels in suction blister-induced epidermal sheets were considerably upregulated as detected by semiquantitative RT-PCR. Furthermore, α-MSH and IL-10 protein levels in blister fluids were significantly increased 24 h after UV irradiation, an effect which could be abolished by the application of the broadspectrum sunscreen AnthéliosXL® prior to UV (SSR) exposure. In addition, enhanced MC-1R mRNA and receptor protein expression upon SSR was ascertained by RT-PCR and immunohistochemistry of the epidermal sheets, respectively. POMC-derived neuropeptides such as α-MSH may therefore play an important role in modulating UV-induced inflammation.