Evaluation of Demodex mite viability using motility and scattered light intensity.

Demodex mites have been suggested to have a role in various cutaneous and ocular disorders pathogenesis, such as rosacea or blepharitis. Evaluation of potential treatments with anti-Demodex effects is difficult because the viability of living mites needs to be evaluated during their exposure to the agent being tested. Mite viability is currently based solely on their observed movement. However, this method of assessing viability has significant limitations as mites may be resting, immobile or paralysed at any given observation point giving the observer a false impression of the organism's death. To overcome this limitation we evaluated a new quantitative method of evaluating the viability of Demodex mites by using scattered light intensity (SLI). We demonstrated that when combined with observation of mite motility, SLI provided increased accuracy of the evaluation of viability of mites being studied. This new viability assay will help address the technical challenges of mite viability experiments. Accurate evaluation of mite viability will enhance mite biology research and allow for more accurate in vitro toxicity assays of proposed anti-mite agents.

Demodex mites modulate sebocyte immune reaction: possible role in the pathogenesis of rosacea.

BACKGROUND: Rosacea is a common facial skin disorder mainly affecting middle-aged adults. Its aetiology is unknown and pathogenesis uncertain. Activation of the host innate immune response has been identified as an important factor. The Demodex mite population in the skin of rosacea patients is significantly higher than in patients with normal skin, suggesting that they may be of aetiological importance in this disorder. OBJECTIVES: To determine the potential of Demodex mites to interact with the host immune system. METHODS: Live Demodex mites were extracted from normal facial skin of control subjects and used in cell stimulation experiments with the immortalized SZ95 sebocyte line. Time- and mite-dose-dependent experiments were performed. Direct effects of Demodex and effects of the medium in which Demodex had been cultured were evaluated on the Toll-like receptor (TLR) signalling pathway on both a gene and protein expression level. RESULTS: Mites modulated TLR signalling events on both mRNA and protein levels in SZ95 sebocytes. An initial trend towards downmodulation of genes in this pathway was observed. A subsequent switch to positive gene upregulation was recorded after 48 h of coculture. Demodex secreted bioactive molecules that affected TLR2 receptor expression by sebocytes. High numbers of Demodex induced proinflammatory cytokine secretion, whereas lower numbers did not. CONCLUSIONS: Demodex mites have the capacity to modulate the TLR signalling pathway of an immortalized human sebocyte line. Mites have the capacity to secrete bioactive molecules that affect the immune reactivity of sebocytes. Increasing mite numbers influenced interleukin-8 secretion by these cells.

Study of Demodex mites: Challenges and Solutions.

Demodex mites are the largest and most complex organisms of the skin microflora. How they interact with the innate and adaptive immune systems is unknown. Their potential to have a pathogenic role in the causation of human skin disorders causes continued speculation. With growing interest in the microflora of human skin and its relevance to cutaneous health, the role of Demodex mites needs to be better understood. The main challenges facing scientists investigating the role of these organisms and possible solutions are reviewed under the following headings: (1) Determining the mite population in skin, (2) Transporting, extracting and imaging live mites, (3) Maintaining mites viable ex vivo and (4) Establishing methods to determine the immune response to Demodex mites and their internal contents.

Epidermal hydration levels in patients with rosacea improve after minocycline therapy.

BACKGROUND: Patients with rosacea frequently report increased skin sensitivity, with features suggestive of an abnormal stratum corneum (SC) permeability barrier. Sebum, pH and hydration levels influence epidermal homeostasis. The correlation of changes in these parameters with clinically effective treatment has not been previously analysed. OBJECTIVES: To analyse sebum, pH and epidermal hydration levels of patients with papulopustular rosacea (PPR) before and after treatment with systemic minocycline. METHODS: We analysed sebum casual levels, pH and hydration along with erythema levels (as a marker of disease activity and response to treatment) on seven designated facial sites of 35 patients with active PPR and compared the results with values on the same sites of 34 control subjects with normal facial skin. To determine the effect of minocycline on these parameters, we re-examined the patients with PPR at the same sites after a 6-week course of treatment. RESULTS: Patients with untreated PPR had significantly increased erythema indices, normal sebum casual levels, a more alkaline centrofacial region and reduced epidermal hydration levels compared with controls. Treatment with minocycline resulted in reduced erythema and increased hydration levels, with the most marked changes evident in the cheeks (13·3% reduction in erythema indices, P < 0·001; 12·4% increase in hydration levels, P = 0·012). There was no change in skin pH or sebum casual levels following treatment. CONCLUSION: Patients with PPR have increased erythema indices, normal sebum casual levels, a more alkaline centrofacial region and reduced epidermal hydration levels compared with control subjects. Treatment with systemic minocycline reduces erythema and increases hydration, in the absence of any change in skin pH or sebum casual levels.

The fatty acid profile of the skin surface lipid layer in papulopustular rosacea.

BACKGROUND: Patients with papulopustular rosacea (PPR) frequently complain of dry, sensitive skin. We have previously demonstrated that patients with PPR have reduced skin surface hydration levels in the presence of normal sebum casual levels, suggesting that it may be the quality and not the quantity of sebum that plays a role in PPR. OBJECTIVES: To compare the sebaceous fatty acid composition of patients with PPR to that of controls with normal facial skin. METHODS: The sebaceous fatty acid composition of 25 patients with PPR and 24 age- and sex-matched controls was analysed by gas chromatography - mass spectrometry. Results Myristic acid (C14:0) was present in greater concentrations in PPR sebum, while the long chain saturated fatty acids arachidic acid (C20:0), behenic acid (C22:0), tricosanoic acid (C23:0) and lignoceric acid (C24:0) as well as the monounsaturated fatty acid cis-11-eicosanoic acid (C20:1) were present in the sebum of patients with PPR in lesser concentrations as compared with controls. CONCLUSIONS: There is increasing evidence that sebaceous fatty acids play a role in the maintenance of skin barrier integrity. We have shown for the first time that patients with PPR have an abnormal sebaceous fatty acid composition, with reduced levels of long chain saturated fatty acids. These new findings may have therapeutic implications for the development of sebum-modifying nonantibiotic treatments for patients with PPR.

The pathophysiology of rosacea.

Rosacea is thought to be a common skin disorder in the general population, presenting with many different clinical features and unknown causes. Theories of pathogenesis have been extrapolated from clinical observation of factors, leading to a definition of the etiology of rosacea which was very limited until recently. A recent upsurge in translational research in rosacea has significantly advanced the insight into this disease. In this review the authors discuss the pathogenesis of this disease, which could be determined by the following factors: 1) exposure to UV radiation; 2) reactive oxygen species (including superoxide and hydroxyl radicals, hydrogen peroxide and singlet oxygen); 3) vascular hyperreactivity; 4) neuropeptides; 5) exacerbation of innate immune response; 6) microbes, in particular H. pylori and environmental aggressors, such as Demodex mite. Even if the recent investigations have significantly improved the understanding of its pathogenesis, the authors conclude that the histopathology of rosacea remains to be clarified according to subtype and age of development of individual lesions.

Calciphylaxis in a patient with normal renal function: response to treatment with sodium thiosulfate.

Calciphylaxis is a rare, life-threatening cause of skin necrosis. The condition is primarily reported in patients with end-stage renal disease, and is associated with significant morbidity and mortality. Treatment has mainly been empirical. We report a case of calciphylaxis in a patient with normal renal function and hypoparathyroidism, who responded to treatment with sodium thiosulfate. To our knowledge, this is the first reported case of the use of sodium thiosulfate to treat calciphylaxis in a patient with normal renal function.

Pyoderma gangrenosum manifesting as a cavitating lung lesion.

We present a case of pyoderma gangrenosum (PG) mimicking a lung carcinoma. A 52-year-old woman presented with an unremitting cough. Computed tomography revealed a cavitating lung lesion. Bronchoscopy and biopsy were interpreted as squamous cell carcinoma. Following a staging mediastinoscopy, a sleeve lobectomy and chest-wall resection was performed. The pulmonary histopathological features suggested Wegener's granulomatosis; no malignancy was found. Three months postoperatively, wound breakdown led to dermatological review. A clinical diagnosis of cutaneous PG was made on the basis of the classic appearance of the surgical wounds and an ulcer on the upper back that had been present before surgery. The patient has been consistently negative for cytoplasmic-staining antineutrophil cytoplasmic antibodies, which supports the diagnosis of PG with cutaneous and pulmonary involvement. Lung manifestations of PG are rare. PG is amenable to systemic therapy. Pulmonary PG is a rare but important differential diagnosis that is not familiar to many physicians and surgeons in this type of presentation.

Mite-related bacterial antigens stimulate inflammatory cells in rosacea.

BACKGROUND: Patients with papulopustular rosacea have a higher density of Demodex folliculorum mites on their faces than normal subjects but the role, if any, of their mites in initiating inflammation is disputed. Selective antibiotics are effective in reducing the inflammatory changes of papulopustular rosacea, but their mode of action is unknown. OBJECTIVES: To investigate whether a D. folliculorum-related bacterium was capable of expressing antigens that could stimulate an inflammatory immune response in patients with rosacea. METHODS: A bacterium (Bacillus oleronius) was isolated from a D. folliculorum mite extracted from the face of a patient with papulopustular rosacea, and was investigated further. RESULTS: This bacterium produced antigens capable of stimulating peripheral blood mononuclear cells proliferation in 16 of 22 (73%) patients with rosacea but only five of 17 (29%) control subjects (P = 0.0105). This antigenic preparation was fractionated into 70 subfractions and the proteins in each fraction were visualized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Western blot analysis revealed the presence of two antigenic proteins of size 62 and 83 kDa in fractions when probing with sera from patients with rosacea. No immunoreactivity to these proteins was recorded when probing with sera from control patients. Two-dimensional electrophoretic separation was used to isolate these proteins and matrix-assisted laser desorption/ionization time-of-flight analysis was employed to identify the relevant peptides. The 62-kDa immunoreactive protein shared amino acid sequence homology with an enzyme involved in carbohydrate metabolism and signal transduction while the 83-kDa protein was similar to bacterial heat shock proteins. CONCLUSIONS: Antigenic proteins related to a bacterium (B. oleronius), isolated from a D. folliculorum mite, have the potential to stimulate an inflammatory response in patients with papulopustular rosacea.

Mycosis fungoides--a review of the management of 28 patients and of the recent literature.

BACKGROUND: Mycosis fungoides is an uncommon cutaneous T-cell lymphoma characterized by malignant monoclonal proliferation of T-helper lymphocytes. Its course is variable with a potential for lymphatic and hematogenous involvement. We report the investigations, staging, treatment, follow-up, and outcome of 28 patients. This is the first such study reported from Ireland. METHODS: Twenty-eight patients with mycosis fungoides (14 women, 14 men; average age, 52.5 years) were reviewed over 12 years in the dermatology clinic which assesses an average of 4500 patients per year. All mycosis fungoides patients were referred from their family physicians. The diagnosis was made in all cases from a combination of clinical findings, histology, and immunohistochemistry. TNM staging revealed 11 patients at diagnosis stage IA (T1), 12 at stage IB (T2), four at stage IIB (T3), and one at stage III (T4). RESULTS: The usual male preponderance was not found. Eight patients needed multiple biopsies to establish the diagnosis. Detailed investigations were not useful in the early stages. Patients were followed up over a 12-year period. Thirteen patients died as a result of cutaneous lymphoma. Two patients with stage IA disease progressed rapidly and died, a feature reported in only 10% of patients at this stage. Five patients showed unusual features, including a long history prior to presentation, the development of the rarely reported bullous mycosis fungoides, and aggressive disease beginning at a young age. CONCLUSIONS: Mycosis fungoides is rare; we reviewed 28 patients over 12 years. The prognosis is poor at the later stages; 13 patients died. Two patients who died were unusual in that they rapidly progressed from stage IA disease; however, in the majority of patients with this stage, the prognosis is excellent. Detailed investigations were unhelpful in early stage disease. Close clinical follow-up is essential to identify disease progression.

Cutaneous sarcoidal reaction in a patient with pulmonary tuberculosis.

Sarcoidosis is a systemic disorder characterized by non-caseating epithelioid granulomas that may affect any organ system. The etiology of sarcoidosis is unknown, but several immune aberrations are thought to play a role in its pathogenesis. The possible role of mycobacterial infection in the pathogenesis of sarcoidosis has been suggested. In recent studies mycobacterial DNA was detected in lung tissues and bronchial lavage fluid of 30% to 50% of patients with sarcoidosis. We report a patient with pulmonary tuberculosis treated successfully three years earlier who developed cutaneous sarcoidosis with negative polymerase chain reaction (PCR) assay for mycobacterial DNA of the skin lesion.

An unusual case of Behçet's syndrome: triggered by typhoid vaccination?

A case of Behçet's syndrome in a 32-year-old woman occurring shortly after her third vaccination against typhoid fever is described. Scleritis and pyoderma gangrenosum were unusual manifestations of BS that occurred in this case. Treatment benefit was provided by mycophenolate mofetil and etanercept. As bacterial antigens have been proposed as potential triggers for the onset of BS, it is possible that the syndrome was precipitated by typhoid vaccination in this patient.